From 047522065ee438fcdad6bb6590a8dba0d8941f0d Mon Sep 17 00:00:00 2001
From: Clemens Portele <portele@interactive-instruments.de>
Date: Sat, 27 Jun 2026 16:12:07 +0200
Subject: [PATCH] improve SQL queries for predicates on main-table columns

A filter predicate on a scalar column of the main feature table was always
encoded as a self-semi-join (A.id IN (SELECT A.id FROM <main> WHERE ...)).
That subquery scans the whole table and the planner does not flatten it, so
its cost grew with the table size rather than with the number of selected
features. Such predicates are now emitted as a direct conjunct on the main
alias. The semi-join form is kept whenever evaluating the predicate requires
a join, junction, or array traversal, where it is load-bearing for
cardinality.

This also fixes a latent bug in the temporal interval (OVERLAPS) encoding,
which hardcoded a trailing parenthesis to close the self-semi-join subquery;
it now preserves the operand expression's suffix so both the inline and the
subquery forms stay balanced. A negated inline predicate is wrapped as
NOT (...).

Updates the golden SQL specs and query fixtures accordingly.
---
 .../features/sql/app/FilterEncoderSql.java    | 49 ++++++++++--
 .../FilterEncoderSqlInResultSetSpec.groovy    | 16 ++--
 .../sql/app/FilterEncoderSqlSpec.groovy       | 80 +++++++++----------
 .../sql/app/SqlQueryTemplatesFixtures.groovy  | 10 +--
 .../sql-queries/self_joins_filter.yml         |  6 +-
 .../resources/sql-queries/simple_filter.yml   |  2 +-
 .../sql-queries/simple_filter_scopes.yml      |  2 +-
 .../simple_filter_scopes_filter.yml           |  2 +-
 8 files changed, 102 insertions(+), 65 deletions(-)

diff --git a/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/FilterEncoderSql.java b/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/FilterEncoderSql.java
index 016749522..054b2e246 100644
--- a/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/FilterEncoderSql.java
+++ b/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/FilterEncoderSql.java
@@ -768,6 +768,20 @@ public String visit(Property property, List<String> children) {
               FilterEncoderSql.this);
       if (!join.isEmpty()) join += " ";
 
+      // When the predicate needs no sub-table join, its operand is a column reachable directly from
+      // the main table (aliased A). Emit it as a direct conjunct instead of a redundant
+      // self-semi-join (A.id IN (SELECT A.id FROM <main> WHERE ...)): that subquery scans the whole
+      // main table and the planner does not flatten it, so it is O(table) per predicate regardless
+      // of how few rows are selected. The semi-join form is kept whenever a join, junction, or
+      // array
+      // traversal is genuinely required (join non-empty) — there it is load-bearing for
+      // cardinality.
+      if (join.isEmpty() && !Objects.equals(table.getParentPath(), ImmutableList.of("_route_"))) {
+        return String.format(
+            "%%1$s%1$s%%2$s",
+            getQualifiedColumn(table, propertyName, "A", allowColumnFallback).first());
+      }
+
       return String.format(
           "A.%3$s IN (SELECT %2$s.%3$s FROM %1$s %2$s %4$sWHERE %%1$s%5$s%%2$s)",
           rootSchema.getName(),
@@ -832,7 +846,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + startColumn
             + ", "
             + endColumn
-            + ")%2$s)";
+            + ")%2$s"
+            + start.substring(start.indexOf("%2$s") + 4);
       } else if (arg1 instanceof Property && arg2 instanceof TemporalLiteral) {
         String startColumn = reduceToColumn(start);
         startColumn =
@@ -844,7 +859,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + startColumn
             + ", "
             + end
-            + ")%2$s)";
+            + ")%2$s"
+            + start.substring(start.indexOf("%2$s") + 4);
       } else if (arg1 instanceof TemporalLiteral && arg2 instanceof Property) {
         String endColumn = reduceToColumn(end);
         endColumn =
@@ -856,7 +872,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + start
             + ", "
             + endColumn
-            + ")%2$s)";
+            + ")%2$s"
+            + end.substring(end.indexOf("%2$s") + 4);
       }
       throw new IllegalStateException("unsupported interval: " + interval);
     }
@@ -1776,6 +1793,23 @@ public String visit(Property property, List<String> children) {
               FilterEncoderSql.this);
       if (!join.isEmpty()) join += " ";
 
+      // When the predicate needs no sub-table join, its operand is a column reachable directly from
+      // the main table (aliased A). Emit it as a direct conjunct instead of a redundant
+      // self-semi-join (A.id IN (SELECT A.id FROM <main> WHERE ...)): that subquery scans the whole
+      // main table and the planner does not flatten it, so it is O(table) per predicate regardless
+      // of how few rows are selected. The semi-join form is kept whenever a join, junction, or
+      // array
+      // traversal is genuinely required (join non-empty) — there it is load-bearing for
+      // cardinality.
+      if (join.isEmpty()
+          && !Objects.equals(table.first().getParentPath(), ImmutableList.of("_route_"))) {
+        return String.format(
+            "%%1$s%1$s%%2$s",
+            getQualifiedColumn(
+                    table.first(), table.second(), propertyName, "A", allowColumnFallback)
+                .first());
+      }
+
       return String.format(
           "A.%3$s IN (SELECT %2$s.%3$s FROM %1$s %2$s %4$sWHERE %%1$s%5$s%%2$s)",
           mapping.getMainTable().getName(),
@@ -1840,7 +1874,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + startColumn
             + ", "
             + endColumn
-            + ")%2$s)";
+            + ")%2$s"
+            + start.substring(start.indexOf("%2$s") + 4);
       } else if (arg1 instanceof Property && arg2 instanceof TemporalLiteral) {
         String startColumn = reduceToColumn(start);
         startColumn =
@@ -1852,7 +1887,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + startColumn
             + ", "
             + end
-            + ")%2$s)";
+            + ")%2$s"
+            + start.substring(start.indexOf("%2$s") + 4);
       } else if (arg1 instanceof TemporalLiteral && arg2 instanceof Property) {
         String endColumn = reduceToColumn(end);
         endColumn =
@@ -1864,7 +1900,8 @@ public String visit(de.ii.xtraplatform.cql.domain.Interval interval, List<String
             + start
             + ", "
             + endColumn
-            + ")%2$s)";
+            + ")%2$s"
+            + end.substring(end.indexOf("%2$s") + 4);
       }
       throw new IllegalStateException("unsupported interval: " + interval);
     }
diff --git a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlInResultSetSpec.groovy b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlInResultSetSpec.groovy
index d88f7b04c..cd6cbd32e 100644
--- a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlInResultSetSpec.groovy
+++ b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlInResultSetSpec.groovy
@@ -79,7 +79,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id = 'foo')) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id = 'foo') SELECT rs_value FROM _rs_0_s1)"
     }
 
     def 'plain id set without a producer filter'() {
@@ -90,7 +90,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A) SELECT rs_value FROM _rs_0_s1)"
     }
 
     def 'plain id set, consumer matches an array property in a junction table'() {
@@ -102,7 +102,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA JOIN externalprovider_externalprovidername AB ON (AA.id=AB.externalprovider_fk) WHERE AB.externalprovidername IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id = 'foo')) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (SELECT AA.id FROM externalprovider AA JOIN externalprovider_externalprovidername AB ON (AA.id=AB.externalprovider_fk) WHERE AB.externalprovidername IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id = 'foo') SELECT rs_value FROM _rs_0_s1))"
     }
 
     def 'chained result sets nest recursively'() {
@@ -115,7 +115,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(outer, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_1_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id = 'foo')), _rs_0_s2 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (SELECT rs_value FROM _rs_1_s1))) SELECT rs_value FROM _rs_0_s2))"
+        sql == "A.id IN (WITH _rs_1_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id = 'foo'), _rs_0_s2 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT rs_value FROM _rs_1_s1)) SELECT rs_value FROM _rs_0_s2)"
     }
 
     def 'an unresolved result set reference is rejected'() {
@@ -145,7 +145,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["simple"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT B.externalprovidername AS rs_value FROM externalprovider A JOIN externalprovider_externalprovidername B ON (A.id=B.externalprovider_fk) WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id = 'foo')) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT B.externalprovidername AS rs_value FROM externalprovider A JOIN externalprovider_externalprovidername B ON (A.id=B.externalprovider_fk) WHERE A.id = 'foo') SELECT rs_value FROM _rs_0_s1)"
     }
 
     def 'projected result set over a column of the main table'() {
@@ -156,7 +156,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A) SELECT rs_value FROM _rs_0_s1)"
     }
 
     def 'the filter of the producer main table is applied to the result set'() {
@@ -167,7 +167,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["simple"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.type = 1)) SELECT rs_value FROM _rs_0_s1))"
+        sql == "A.id IN (WITH _rs_0_s1 AS MATERIALIZED (SELECT A.id AS rs_value FROM externalprovider A WHERE A.type = 1) SELECT rs_value FROM _rs_0_s1)"
     }
 
     def 'a materialized result set is inlined as a literal IN list'() {
@@ -182,7 +182,7 @@ class FilterEncoderSqlInResultSetSpec extends Specification {
         def sql = filterEncoder.encode(filter, mappings["value_array"])
 
         then:
-        sql == "A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.id IN ('foo', 'bar'))"
+        sql == "A.id IN ('foo', 'bar')"
     }
 
     def 'an empty materialized result set yields a false predicate'() {
diff --git a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlSpec.groovy b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlSpec.groovy
index cc4a78655..fba86bff1 100644
--- a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlSpec.groovy
+++ b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/FilterEncoderSqlSpec.groovy
@@ -176,7 +176,7 @@ class FilterEncoderSqlSpec extends Specification {
                 ])
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.name || ' (' || AA.created || ')' = 'Kupp (Serrig)')"
+        String expected = "A.name || ' (' || A.created || ')' = 'Kupp (Serrig)'"
 
         String actual = filterEncoderCustomConcatPgis.encode(filter, instanceContainer)
 
@@ -196,7 +196,7 @@ class FilterEncoderSqlSpec extends Specification {
                 ])
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE concat(AA.name, ' (', AA.created, ')') = 'Kupp (Serrig)')"
+        String expected = "concat(A.name, ' (', A.created, ')') = 'Kupp (Serrig)'"
 
         String actual = filterEncoderCustomConcatGpkg.encode(filter, instanceContainer)
 
@@ -235,7 +235,7 @@ class FilterEncoderSqlSpec extends Specification {
                 ])
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE concat(AA.name, '-', 'x') = 'foo-x')"
+        String expected = "concat(A.name, '-', 'x') = 'foo-x'"
 
         String actual = filterEncoderCustom.encode(filter, instanceContainer)
 
@@ -252,7 +252,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Function.of("my_upper_match", [Property.of("name"), ScalarLiteral.of("kupp%")])
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE UPPER(AA.name) LIKE UPPER('kupp%'))"
+        String expected = "UPPER(A.name) LIKE UPPER('kupp%')"
 
         String actual = filterEncoderCustomBoolean.encode(filter, instanceContainer)
 
@@ -268,7 +268,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Function.of("ist_in_bereich", [Property.of("location"), ScalarLiteral.of("Bereich Saar")])
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, (SELECT geometrie FROM bereiche WHERE name='Bereich Saar')))"
+        String expected = "ST_Intersects(A.location, (SELECT geometrie FROM bereiche WHERE name='Bereich Saar'))"
 
         String actual = filterEncoderCustomGeometry.encode(filter, instanceContainer)
 
@@ -284,7 +284,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_15
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Within(AA.location, ST_GeomFromText('POLYGON((-118.0 33.8,-117.9 33.8,-117.9 34.0,-118.0 34.0,-118.0 33.8))',4326)))"
+        String expected = "ST_Within(A.location, ST_GeomFromText('POLYGON((-118.0 33.8,-117.9 33.8,-117.9 34.0,-118.0 34.0,-118.0 33.8))',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -301,7 +301,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_15)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE NOT ST_Within(AA.location, ST_GeomFromText('POLYGON((-118.0 33.8,-117.9 33.8,-117.9 34.0,-118.0 34.0,-118.0 33.8))',4326)))"
+        String expected = "NOT (ST_Within(A.location, ST_GeomFromText('POLYGON((-118.0 33.8,-117.9 33.8,-117.9 34.0,-118.0 34.0,-118.0 33.8))',4326)))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -353,7 +353,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_15_RandomCrs
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Within(AA.location, ST_GeomFromText('POLYGON((-118.0 33.8,-118.0 34.0,-117.9 34.0,-117.9 33.8,-118.0 33.8))',4326)))"
+        String expected = "ST_Within(A.location, ST_GeomFromText('POLYGON((-118.0 33.8,-118.0 34.0,-117.9 34.0,-117.9 33.8,-118.0 33.8))',4326))"
 
         String actual = filterEncoder2.encode(filter, instanceContainer)
 
@@ -368,7 +368,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_12
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.built::timestamp(0) < TIMESTAMP '2012-06-05T00:00:00Z')"
+        String expected = "A.built::timestamp(0) < TIMESTAMP '2012-06-05T00:00:00Z'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -385,7 +385,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_12)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.built::timestamp(0) >= TIMESTAMP '2012-06-05T00:00:00Z')"
+        String expected = "A.built::timestamp(0) >= TIMESTAMP '2012-06-05T00:00:00Z'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -402,7 +402,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_12_date
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.built::date < DATE '2012-06-05')"
+        String expected = "A.built::date < DATE '2012-06-05'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -419,7 +419,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_12_date)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.built::date >= DATE '2012-06-05')"
+        String expected = "A.built::date >= DATE '2012-06-05'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -436,7 +436,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_14
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE AA.updated::timestamp(0) > TIMESTAMP '2017-06-10T07:30:00Z') AND A.id IN (SELECT AA.id FROM building AA WHERE AA.updated::timestamp(0) < TIMESTAMP '2017-06-11T10:30:00Z'))"
+        String expected = "(A.updated::timestamp(0) > TIMESTAMP '2017-06-10T07:30:00Z' AND A.updated::timestamp(0) < TIMESTAMP '2017-06-11T10:30:00Z')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -453,7 +453,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_14_B
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE TIMESTAMP '2017-06-10T07:30:00Z' > AA.updated::timestamp(0)) AND A.id IN (SELECT AA.id FROM building AA WHERE TIMESTAMP '2017-06-11T10:30:00Z' < AA.updated::timestamp(0)))"
+        String expected = "(TIMESTAMP '2017-06-10T07:30:00Z' > A.updated::timestamp(0) AND TIMESTAMP '2017-06-11T10:30:00Z' < A.updated::timestamp(0))"
         String actual = filterEncoder.encode(filter, instanceContainer)
 
         then:
@@ -469,7 +469,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_Interval
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE (TIMESTAMP '2017-06-10T07:30:00Z', TIMESTAMP '2017-06-11T10:30:00Z') OVERLAPS (TIMESTAMP '2012-06-05T00:00:00Z', COALESCE(AA.end,TIMESTAMP 'infinity')))"
+        String expected = "(TIMESTAMP '2017-06-10T07:30:00Z', TIMESTAMP '2017-06-11T10:30:00Z') OVERLAPS (TIMESTAMP '2012-06-05T00:00:00Z', COALESCE(A.end,TIMESTAMP 'infinity'))"
         String actual = filterEncoder.encode(filter, instanceContainer)
 
         then:
@@ -485,7 +485,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_Illegal_Interval
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE TIMESTAMP '2017-06-10T07:30:00Z' > AA.updated::timestamp(0)) AND A.id IN (SELECT AA.id FROM building AA WHERE TIMESTAMP '2017-06-11T10:30:00Z' < AA.updated::timestamp(0)))"
+        String expected = "(TIMESTAMP '2017-06-10T07:30:00Z' > A.updated::timestamp(0) AND TIMESTAMP '2017-06-11T10:30:00Z' < A.updated::timestamp(0))"
         String actual = filterEncoder.encode(filter, instanceContainer)
 
         then:
@@ -501,7 +501,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_14_Negation
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE AA.updated::timestamp(0) <= TIMESTAMP '2017-06-10T07:30:00Z') OR A.id IN (SELECT AA.id FROM building AA WHERE AA.updated::timestamp(0) >= TIMESTAMP '2017-06-11T10:30:00Z'))"
+        String expected = "(A.updated::timestamp(0) <= TIMESTAMP '2017-06-10T07:30:00Z' OR A.updated::timestamp(0) >= TIMESTAMP '2017-06-11T10:30:00Z')"
         String actual = filterEncoder.encode(filter, instanceContainer)
 
         then:
@@ -517,7 +517,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_20
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.owner IS NULL)"
+        String expected = "A.owner IS NULL"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -534,7 +534,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_20)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.owner IS NOT NULL)"
+        String expected = "A.owner IS NOT NULL"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -551,7 +551,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_40
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.owner NOT IN ('Mike','John','Tom'))"
+        String expected = "A.owner NOT IN ('Mike','John','Tom')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -568,7 +568,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_3
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.owner::varchar LIKE '% Jones %')"
+        String expected = "A.owner::varchar LIKE '% Jones %'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -585,7 +585,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_3)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.owner::varchar NOT LIKE '% Jones %')"
+        String expected = "A.owner::varchar NOT LIKE '% Jones %'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -602,7 +602,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_CASEI
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE LOWER(AA.road_class) IN ('οδος','straße'))"
+        String expected = "LOWER(A.road_class) IN ('οδος','straße')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -619,7 +619,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_CASEI)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE LOWER(AA.road_class) NOT IN ('οδος','straße'))"
+        String expected = "LOWER(A.road_class) NOT IN ('οδος','straße')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -636,7 +636,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_ACCENTI
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE LOWER(AA.road_class) IN ('οδος','straße'))"
+        String expected = "LOWER(A.road_class) IN ('οδος','straße')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -653,7 +653,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_ACCENTI)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE LOWER(AA.road_class) NOT IN ('οδος','straße'))"
+        String expected = "LOWER(A.road_class) NOT IN ('οδος','straße')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -670,7 +670,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('POLYGON((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0))',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('POLYGON((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0))',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -687,7 +687,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_16)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE NOT ST_Intersects(AA.location, ST_GeomFromText('POLYGON((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0))',4326)))"
+        String expected = "NOT (ST_Intersects(A.location, ST_GeomFromText('POLYGON((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0))',4326)))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -805,7 +805,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_25z
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE (COALESCE(AA.start,TIMESTAMP '-infinity'), TIMESTAMP 'infinity') OVERLAPS (DATE '2017-06-10',TIMESTAMP 'infinity'))"
+        String expected = "(COALESCE(A.start,TIMESTAMP '-infinity'), TIMESTAMP 'infinity') OVERLAPS (DATE '2017-06-10',TIMESTAMP 'infinity')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -822,7 +822,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_25y
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE (COALESCE(AA.start,TIMESTAMP '-infinity'), COALESCE(AA.end,TIMESTAMP 'infinity')) OVERLAPS (DATE '2017-06-10',DATE '2017-06-12'))"
+        String expected = "(COALESCE(A.start,TIMESTAMP '-infinity'), COALESCE(A.end,TIMESTAMP 'infinity')) OVERLAPS (DATE '2017-06-10',DATE '2017-06-12')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -839,7 +839,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_25y)
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE NOT (COALESCE(AA.start,TIMESTAMP '-infinity'), COALESCE(AA.end,TIMESTAMP 'infinity')) OVERLAPS (DATE '2017-06-10',DATE '2017-06-12'))"
+        String expected = "NOT ((COALESCE(A.start,TIMESTAMP '-infinity'), COALESCE(A.end,TIMESTAMP 'infinity')) OVERLAPS (DATE '2017-06-10',DATE '2017-06-12'))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -856,7 +856,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16_MultiPolygon
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('MULTIPOLYGON(((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0)),((-15.0 -15.0,15.0 -15.0,15.0 15.0,-15.0 -15.0)))',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('MULTIPOLYGON(((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0)),((-15.0 -15.0,15.0 -15.0,15.0 15.0,-15.0 -15.0)))',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -873,7 +873,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16_MultiLineString
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('MULTILINESTRING((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0),(-15.0 -15.0,15.0 -15.0,15.0 15.0,-15.0 -15.0))',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('MULTILINESTRING((-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0),(-15.0 -15.0,15.0 -15.0,15.0 15.0,-15.0 -15.0))',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -890,7 +890,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16_LineString
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('LINESTRING(-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0)',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('LINESTRING(-10.0 -10.0,10.0 -10.0,10.0 10.0,-10.0 -10.0)',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -907,7 +907,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16_Point
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('POINT(10.0 -10.0)',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('POINT(10.0 -10.0)',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -924,7 +924,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_16_MultiPoint
 
         when:
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE ST_Intersects(AA.location, ST_GeomFromText('MULTIPOINT(10.0 -10.0,10.0 10.0)',4326)))"
+        String expected = "ST_Intersects(A.location, ST_GeomFromText('MULTIPOINT(10.0 -10.0,10.0 10.0)',4326))"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -941,7 +941,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_26
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE AA.updated > TIMESTAMP '2017-06-10T07:30:00Z') AND A.id IN (SELECT AA.id FROM building AA WHERE AA.updated < TIMESTAMP 'infinity'))"
+        String expected = "(A.updated > TIMESTAMP '2017-06-10T07:30:00Z' AND A.updated < TIMESTAMP 'infinity')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -958,7 +958,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = Not.of(CqlFilterExamples.EXAMPLE_26)
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE AA.updated <= TIMESTAMP '2017-06-10T07:30:00Z') OR A.id IN (SELECT AA.id FROM building AA WHERE AA.updated >= TIMESTAMP 'infinity'))"
+        String expected = "(A.updated <= TIMESTAMP '2017-06-10T07:30:00Z' OR A.updated >= TIMESTAMP 'infinity')"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -1026,7 +1026,7 @@ class FilterEncoderSqlSpec extends Specification {
         def filter = CqlFilterExamples.EXAMPLE_NOT
 
         when:
-        String expected = "(A.id IN (SELECT AA.id FROM building AA WHERE AA.test = 1) OR (A.id IN (SELECT AA.id FROM building AA WHERE AA.test1 <> 1) AND A.id IN (SELECT AA.id FROM building AA WHERE AA.test2 = 'foo') AND A.id IN (SELECT AA.id FROM building AA WHERE AA.test3 <= 'bar')) OR (A.id IN (SELECT AA.id FROM building AA WHERE AA.test1 <> 1) OR A.id IN (SELECT AA.id FROM building AA WHERE AA.test2 = 'foo') OR A.id IN (SELECT AA.id FROM building AA WHERE AA.test3 <= 'bar')) OR A.id IN (SELECT AA.id FROM building AA WHERE AA.test <> 1))"
+        String expected = "(A.test = 1 OR (A.test1 <> 1 AND A.test2 = 'foo' AND A.test3 <= 'bar') OR (A.test1 <> 1 OR A.test2 = 'foo' OR A.test3 <= 'bar') OR A.test <> 1)"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
@@ -1043,7 +1043,7 @@ class FilterEncoderSqlSpec extends Specification {
 
         when:
         // ALIKE returns BOOLEAN — used directly as filter predicate
-        String expected = "A.id IN (SELECT AA.id FROM building AA WHERE AA.name::varchar LIKE 'kupp%')"
+        String expected = "A.name::varchar LIKE 'kupp%'"
 
         String actual = filterEncoder.encode(filter, instanceContainer)
 
diff --git a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/SqlQueryTemplatesFixtures.groovy b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/SqlQueryTemplatesFixtures.groovy
index f0208700d..27d32cc74 100644
--- a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/SqlQueryTemplatesFixtures.groovy
+++ b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/SqlQueryTemplatesFixtures.groovy
@@ -43,8 +43,8 @@ class SqlQueryTemplatesFixtures {
             "  SELECT * FROM NR, NM, NS"
 
     static String META_FILTER = "WITH\n" +
-            "    NR AS (SELECT MIN(SKEY) AS minKey, MAX(SKEY) AS maxKey, count(*) AS numberReturned FROM (SELECT A.id AS SKEY FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.type = 1) ORDER BY SKEY LIMIT 10 OFFSET 10) AS IDS),\n" +
-            "    NM AS (SELECT count(*) AS numberMatched FROM (SELECT A.id AS SKEY FROM externalprovider A WHERE A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.type = 1) ORDER BY 1) AS IDS),\n" +
+            "    NR AS (SELECT MIN(SKEY) AS minKey, MAX(SKEY) AS maxKey, count(*) AS numberReturned FROM (SELECT A.id AS SKEY FROM externalprovider A WHERE A.type = 1 ORDER BY SKEY LIMIT 10 OFFSET 10) AS IDS),\n" +
+            "    NM AS (SELECT count(*) AS numberMatched FROM (SELECT A.id AS SKEY FROM externalprovider A WHERE A.type = 1 ORDER BY 1) AS IDS),\n" +
             "    NS AS (SELECT -1::bigint AS numberSkipped)\n" +
             "  SELECT * FROM NR, NM, NS"
 
@@ -70,9 +70,9 @@ class SqlQueryTemplatesFixtures {
     ]
 
     static List<String> SELF_JOINS_FILTER = [
-            "SELECT A.id AS SKEY, A.oid FROM building A WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1)) ORDER BY 1",
-            "SELECT A.id AS SKEY, B.id AS SKEY_1, B.id FROM building A JOIN building B ON (A.id=B.fk_buildingpart_parent AND (B.id > 100)) WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1)) ORDER BY 1,2",
-            "SELECT A.id AS SKEY, B.id AS SKEY_1, B.id FROM building A JOIN building B ON (A.fk_buildingpart_parent=B.id AND (B.id > 1000)) WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1)) ORDER BY 1,2"
+            "SELECT A.id AS SKEY, A.oid FROM building A WHERE (A.oid > 1) ORDER BY 1",
+            "SELECT A.id AS SKEY, B.id AS SKEY_1, B.id FROM building A JOIN building B ON (A.id=B.fk_buildingpart_parent AND (B.id > 100)) WHERE (A.oid > 1) ORDER BY 1,2",
+            "SELECT A.id AS SKEY, B.id AS SKEY_1, B.id FROM building A JOIN building B ON (A.fk_buildingpart_parent=B.id AND (B.id > 1000)) WHERE (A.oid > 1) ORDER BY 1,2"
     ]
 
     static List<String> SELF_JOIN_NESTED_DUPLICATE = [
diff --git a/xtraplatform-features-sql/src/test/resources/sql-queries/self_joins_filter.yml b/xtraplatform-features-sql/src/test/resources/sql-queries/self_joins_filter.yml
index 9754d6d0d..f245dd3f8 100644
--- a/xtraplatform-features-sql/src/test/resources/sql-queries/self_joins_filter.yml
+++ b/xtraplatform-features-sql/src/test/resources/sql-queries/self_joins_filter.yml
@@ -1,17 +1,17 @@
 - >-
   SELECT A.id AS SKEY, A.oid
   FROM building A
-  WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1))
+  WHERE (A.oid > 1)
   ORDER BY 1
 - >-
   SELECT A.id AS SKEY, B.id AS SKEY_1, B.id
   FROM building A
   JOIN building B ON (A.id=B.fk_buildingpart_parent AND (B.id > 100))
-  WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1))
+  WHERE (A.oid > 1)
   ORDER BY 1,2
 - >-
   SELECT A.id AS SKEY, B.id AS SKEY_1, B.id
   FROM building A
   JOIN building B ON (A.fk_buildingpart_parent=B.id AND (B.id > 1000))
-  WHERE (A.id IN (SELECT AA.id FROM building AA WHERE AA.oid > 1))
+  WHERE (A.oid > 1)
   ORDER BY 1,2
\ No newline at end of file
diff --git a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter.yml b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter.yml
index d14081e56..f3782f1e1 100644
--- a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter.yml
+++ b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter.yml
@@ -1,5 +1,5 @@
 - >-
   SELECT A.id AS SKEY, A.id
   FROM externalprovider A
-  WHERE (A.id IN (SELECT AA.id FROM externalprovider AA WHERE AA.type = 1))
+  WHERE (A.type = 1)
   ORDER BY 1
\ No newline at end of file
diff --git a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes.yml b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes.yml
index f0cfdadd0..92c2d655d 100644
--- a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes.yml
+++ b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes.yml
@@ -1,5 +1,5 @@
 - >-
   SELECT A.id AS SKEY, A.id
   FROM coretable A
-  WHERE (A.id IN (SELECT AA.id FROM coretable AA WHERE AA.featuretype = 'BP_BaugebietsTeilFlaeche'))
+  WHERE (A.featuretype = 'BP_BaugebietsTeilFlaeche')
   ORDER BY 1
diff --git a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes_filter.yml b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes_filter.yml
index cc6ba1724..ebef85882 100644
--- a/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes_filter.yml
+++ b/xtraplatform-features-sql/src/test/resources/sql-queries/simple_filter_scopes_filter.yml
@@ -1,5 +1,5 @@
 - >-
   SELECT A.id AS SKEY, A.id
   FROM coretable A
-  WHERE ((A.id IN (SELECT AA.id FROM coretable AA WHERE AA.featuretype = 'BP_BaugebietsTeilFlaeche') AND A.id IN (SELECT AA.id FROM coretable AA JOIN refs AB ON (AA.id=AB.related_id AND (AB.rel = 'texte')) WHERE AB.base_id = 'foo')))
+  WHERE ((A.featuretype = 'BP_BaugebietsTeilFlaeche' AND A.id IN (SELECT AA.id FROM coretable AA JOIN refs AB ON (AA.id=AB.related_id AND (AB.rel = 'texte')) WHERE AB.base_id = 'foo')))
   ORDER BY 1