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Indexes with INCLUDE columns and their support in B-tree

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This patch introduces INCLUDE clause to index definition.  This clause
specifies a list of columns which will be included as a non-key part in
the index.  The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans.  Also, such columns don't need to have
appropriate operator classes.  Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.

Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine.  For now, only B-tree indexes support INCLUDE clause.

In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys).  Therefore, B-tree indexes
now might have variable number of attributes.  This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid.  Free 13th bit of t_info is used for indicating
that.  This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.

Bump catalog version

Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
			 David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru
This commit is contained in:
Teodor Sigaev
2018-04-07 23:00:39 +03:00
parent 01bb85169a
commit 8224de4f42
89 changed files with 2112 additions and 467 deletions
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63
src/backend/commands/indexcmds.c
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@ -109,8 +109,10 @@ static void ReindexPartitionedIndex(Relation parentIdx);
* indexes. We acknowledge this when all operator classes, collations and
* exclusion operators match. Though we could further permit intra-opfamily
* changes for btree and hash indexes, that adds subtle complexity with no
* concrete benefit for core types.
* concrete benefit for core types. Note, that INCLUDE columns aren't
* checked by this function, for them it's enough that table rewrite is
* skipped.
*
* When a comparison or exclusion operator has a polymorphic input type, the
* actual input types must also match. This defends against the possibility
* that operators could vary behavior in response to get_fn_expr_argtype().
@ -224,7 +226,7 @@ CheckIndexCompatible(Oid oldId,
}
/* Any change in operator class or collation breaks compatibility. */
old_natts = indexForm->indnatts;
old_natts = indexForm->indnkeyatts;
Assert(old_natts == numberOfAttributes);
d = SysCacheGetAttr(INDEXRELID, tuple, Anum_pg_index_indcollation, &isnull);
@ -351,6 +353,7 @@ DefineIndex(Oid relationId,
bits16 flags;
bits16 constr_flags;
int numberOfAttributes;
int numberOfKeyAttributes;
TransactionId limitXmin;
VirtualTransactionId *old_snapshots;
ObjectAddress address;
@ -361,10 +364,28 @@ DefineIndex(Oid relationId,
Snapshot snapshot;
int i;
if (list_intersection(stmt->indexParams, stmt->indexIncludingParams) != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("included columns must not intersect with key columns")));
/*
* count attributes in index
* count key attributes in index
*/
numberOfKeyAttributes = list_length(stmt->indexParams);
/*
* We append any INCLUDE columns onto the indexParams list so that we have
* one list with all columns. Later we can determine which of these are
* key columns, and which are just part of the INCLUDE list by checking
* the list position. A list item in a position less than
* ii_NumIndexKeyAttrs is part of the key columns, and anything equal to
* and over is part of the INCLUDE columns.
*/
stmt->indexParams = list_concat(stmt->indexParams,
stmt->indexIncludingParams);
numberOfAttributes = list_length(stmt->indexParams);
if (numberOfAttributes <= 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
@ -568,6 +589,11 @@ DefineIndex(Oid relationId,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("access method \"%s\" does not support unique indexes",
accessMethodName)));
if (list_length(stmt->indexIncludingParams) > 0 && !amRoutine->amcaninclude)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("access method \"%s\" does not support included columns",
accessMethodName)));
if (numberOfAttributes > 1 && !amRoutine->amcanmulticol)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@ -605,6 +631,7 @@ DefineIndex(Oid relationId,
*/
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);
@ -624,7 +651,7 @@ DefineIndex(Oid relationId,
typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
classObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
classObjectId = (Oid *) palloc(numberOfKeyAttributes * sizeof(Oid));
coloptions = (int16 *) palloc(numberOfAttributes * sizeof(int16));
ComputeIndexAttrs(indexInfo,
typeObjectId, collationObjectId, classObjectId,
@ -1348,16 +1375,15 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
ListCell *nextExclOp;
ListCell *lc;
int attn;
int nkeycols = indexInfo->ii_NumIndexKeyAttrs;
/* Allocate space for exclusion operator info, if needed */
if (exclusionOpNames)
{
int ncols = list_length(attList);
Assert(list_length(exclusionOpNames) == ncols);
indexInfo->ii_ExclusionOps = (Oid *) palloc(sizeof(Oid) * ncols);
indexInfo->ii_ExclusionProcs = (Oid *) palloc(sizeof(Oid) * ncols);
indexInfo->ii_ExclusionStrats = (uint16 *) palloc(sizeof(uint16) * ncols);
Assert(list_length(exclusionOpNames) == nkeycols);
indexInfo->ii_ExclusionOps = (Oid *) palloc(sizeof(Oid) * nkeycols);
indexInfo->ii_ExclusionProcs = (Oid *) palloc(sizeof(Oid) * nkeycols);
indexInfo->ii_ExclusionStrats = (uint16 *) palloc(sizeof(uint16) * nkeycols);
nextExclOp = list_head(exclusionOpNames);
}
else
@ -1410,6 +1436,11 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
Node *expr = attribute->expr;
Assert(expr != NULL);
if (attn >= nkeycols)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("expressions are not supported in included columns")));
atttype = exprType(expr);
attcollation = exprCollation(expr);
@ -1487,6 +1518,16 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
collationOidP[attn] = attcollation;
/*
* Skip opclass and ordering options for included columns.
*/
if (attn >= nkeycols)
{
colOptionP[attn] = 0;
attn++;
continue;
}
/*
* Identify the opclass to use.
*/