Fix handling of expressions and predicates in REINDEX CONCURRENTLY

When copying the definition of an index rebuilt concurrently for the new
entry, the index information was taken directly from the old index using
the relation cache.  In this case, predicates and expressions have
some post-processing to prepare things for the planner, which loses some
information including the collations added in any of them.

This inconsistency can cause issues when attempting for example a table
rewrite, and makes the new indexes rebuilt concurrently inconsistent
with the old entries.

In order to fix the problem, fetch expressions and predicates directly
from the catalog of the old entry, and fill in IndexInfo for the new
index with that.  This makes the process more consistent with
DefineIndex(), and the code is refactored with the addition of a routine
to create an IndexInfo node.

Reported-by: Manuel Rigger
Author: Michael Paquier
Discussion: https://postgr.es/m/CA+u7OA5Hp0ra235F3czPom_FyAd-3+XwSJmX95r1+sRPOJc9VQ@mail.gmail.com
Backpatch-through: 12

1 files changed, 13 insertions, 33 deletions

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index fd299273c5a..8dc7a398706 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -202,18 +202,8 @@ CheckIndexCompatible(Oid oldId,
 	 * contains only key attributes, thus we're filling ii_NumIndexAttrs and
 	 * ii_NumIndexKeyAttrs with same value.
 	 */
-	indexInfo = makeNode(IndexInfo);
-	indexInfo->ii_NumIndexAttrs = numberOfAttributes;
-	indexInfo->ii_NumIndexKeyAttrs = numberOfAttributes;
-	indexInfo->ii_Expressions = NIL;
-	indexInfo->ii_ExpressionsState = NIL;
-	indexInfo->ii_PredicateState = NULL;
-	indexInfo->ii_ExclusionOps = NULL;
-	indexInfo->ii_ExclusionProcs = NULL;
-	indexInfo->ii_ExclusionStrats = NULL;
-	indexInfo->ii_Am = accessMethodId;
-	indexInfo->ii_AmCache = NULL;
-	indexInfo->ii_Context = CurrentMemoryContext;
+	indexInfo = makeIndexInfo(numberOfAttributes, numberOfAttributes,
+							  accessMethodId, NIL, NIL, false, false, false);
 	typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
 	collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
 	classObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
@@ -780,27 +770,17 @@ DefineIndex(Oid relationId,
 
 	/*
 	 * Prepare arguments for index_create, primarily an IndexInfo structure.
-	 * Note that ii_Predicate must be in implicit-AND format.
-	 */
-	indexInfo = makeNode(IndexInfo);
-	indexInfo->ii_NumIndexAttrs = numberOfAttributes;
-	indexInfo->ii_NumIndexKeyAttrs = numberOfKeyAttributes;
-	indexInfo->ii_Expressions = NIL;	/* for now */
-	indexInfo->ii_ExpressionsState = NIL;
-	indexInfo->ii_Predicate = make_ands_implicit((Expr *) stmt->whereClause);
-	indexInfo->ii_PredicateState = NULL;
-	indexInfo->ii_ExclusionOps = NULL;
-	indexInfo->ii_ExclusionProcs = NULL;
-	indexInfo->ii_ExclusionStrats = NULL;
-	indexInfo->ii_Unique = stmt->unique;
-	/* In a concurrent build, mark it not-ready-for-inserts */
-	indexInfo->ii_ReadyForInserts = !stmt->concurrent;
-	indexInfo->ii_Concurrent = stmt->concurrent;
-	indexInfo->ii_BrokenHotChain = false;
-	indexInfo->ii_ParallelWorkers = 0;
-	indexInfo->ii_Am = accessMethodId;
-	indexInfo->ii_AmCache = NULL;
-	indexInfo->ii_Context = CurrentMemoryContext;
+	 * Note that predicates must be in implicit-AND format.  In a concurrent
+	 * build, mark it not-ready-for-inserts.
+	 */
+	indexInfo = makeIndexInfo(numberOfAttributes,
+							  numberOfKeyAttributes,
+							  accessMethodId,
+							  NIL,	/* expressions, NIL for now */
+							  make_ands_implicit((Expr *) stmt->whereClause),
+							  stmt->unique,
+							  !stmt->concurrent,
+							  stmt->concurrent);
 
 	typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
 	collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));