Replace functional-index facility with expressional indexes. Any column

of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects).  This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up.  Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.

4 files changed, 32 insertions, 2 deletions

diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 243198d79f2..d82ed8c4e89 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -81,3 +81,17 @@ INSERT INTO func_index_heap VALUES('ABCD', 'EF');
 ERROR:  Cannot insert a duplicate key into unique index func_index_index
 -- but this shouldn't:
 INSERT INTO func_index_heap VALUES('QWERTY');
+--
+-- Same test, expressional index
+--
+DROP TABLE func_index_heap;
+CREATE TABLE func_index_heap (f1 text, f2 text);
+CREATE UNIQUE INDEX func_index_index on func_index_heap ((f1 || f2) text_ops);
+INSERT INTO func_index_heap VALUES('ABC','DEF');
+INSERT INTO func_index_heap VALUES('AB','CDEFG');
+INSERT INTO func_index_heap VALUES('QWE','RTY');
+-- this should fail because of unique index:
+INSERT INTO func_index_heap VALUES('ABCD', 'EF');
+ERROR:  Cannot insert a duplicate key into unique index func_index_index
+-- but this shouldn't:
+INSERT INTO func_index_heap VALUES('QWERTY');
diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out
index 2dd74613d99..87e1943e5a2 100644
--- a/src/test/regress/expected/sanity_check.out
+++ b/src/test/regress/expected/sanity_check.out
@@ -75,7 +75,7 @@ FROM pg_class c LEFT JOIN pg_namespace n ON n.oid = relnamespace
 WHERE relhasoids
     AND ((nspname ~ '^pg_') IS NOT FALSE)
     AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
-                    AND indkey[0] = -2 AND indkey[1] = 0 AND indisunique);
+                    AND indkey[0] = -2 AND indnatts = 1 AND indisunique);
  relname | nspname 
 ---------+---------
 (0 rows)
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index fe49d4ec2e2..383a7a1a9f9 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -104,3 +104,19 @@ INSERT INTO func_index_heap VALUES('QWE','RTY');
 INSERT INTO func_index_heap VALUES('ABCD', 'EF');
 -- but this shouldn't:
 INSERT INTO func_index_heap VALUES('QWERTY');
+
+
+--
+-- Same test, expressional index
+--
+DROP TABLE func_index_heap;
+CREATE TABLE func_index_heap (f1 text, f2 text);
+CREATE UNIQUE INDEX func_index_index on func_index_heap ((f1 || f2) text_ops);
+
+INSERT INTO func_index_heap VALUES('ABC','DEF');
+INSERT INTO func_index_heap VALUES('AB','CDEFG');
+INSERT INTO func_index_heap VALUES('QWE','RTY');
+-- this should fail because of unique index:
+INSERT INTO func_index_heap VALUES('ABCD', 'EF');
+-- but this shouldn't:
+INSERT INTO func_index_heap VALUES('QWERTY');
diff --git a/src/test/regress/sql/sanity_check.sql b/src/test/regress/sql/sanity_check.sql
index 50b1a2659b2..108d4f78124 100644
--- a/src/test/regress/sql/sanity_check.sql
+++ b/src/test/regress/sql/sanity_check.sql
@@ -21,4 +21,4 @@ FROM pg_class c LEFT JOIN pg_namespace n ON n.oid = relnamespace
 WHERE relhasoids
     AND ((nspname ~ '^pg_') IS NOT FALSE)
     AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
-                    AND indkey[0] = -2 AND indkey[1] = 0 AND indisunique);
+                    AND indkey[0] = -2 AND indnatts = 1 AND indisunique);