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| author | Peter Eisentraut <peter@eisentraut.org> | 2024-01-24 15:43:41 +0100 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2024-01-24 16:34:37 +0100 |
| commit | 46a0cd4cefb4d9b462d8cc4df5e7ecdd190bea92 (patch) | |
| tree | ccbcef511474ad69dd7472f0a35fe7813e47d909 /src/backend/parser/parse_utilcmd.c | |
| parent | 74a73063106583b1f49274a2cd1df42e35107361 (diff) | |
| download | postgresql-46a0cd4cefb4d9b462d8cc4df5e7ecdd190bea92.tar.gz postgresql-46a0cd4cefb4d9b462d8cc4df5e7ecdd190bea92.zip | |
Add temporal PRIMARY KEY and UNIQUE constraints
Add WITHOUT OVERLAPS clause to PRIMARY KEY and UNIQUE constraints.
These are backed by GiST indexes instead of B-tree indexes, since they
are essentially exclusion constraints with = for the scalar parts of
the key and && for the temporal part.
Author: Paul A. Jungwirth <pj@illuminatedcomputing.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+renyUApHgSZF9-nd-a0+OPGharLQLO=mDHcY4_qQ0+noCUVg@mail.gmail.com
Diffstat (limited to 'src/backend/parser/parse_utilcmd.c')
| -rw-r--r-- | src/backend/parser/parse_utilcmd.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c index b2d1fa9d0d6..56ac4f516ea 100644 --- a/src/backend/parser/parse_utilcmd.c +++ b/src/backend/parser/parse_utilcmd.c @@ -1716,6 +1716,7 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx, index->unique = idxrec->indisunique; index->nulls_not_distinct = idxrec->indnullsnotdistinct; index->primary = idxrec->indisprimary; + index->iswithoutoverlaps = (idxrec->indisprimary || idxrec->indisunique) && idxrec->indisexclusion; index->transformed = true; /* don't need transformIndexStmt */ index->concurrent = false; index->if_not_exists = false; @@ -1765,7 +1766,9 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx, int nElems; int i; - Assert(conrec->contype == CONSTRAINT_EXCLUSION); + Assert(conrec->contype == CONSTRAINT_EXCLUSION || + (index->iswithoutoverlaps && + (conrec->contype == CONSTRAINT_PRIMARY || conrec->contype == CONSTRAINT_UNIQUE))); /* Extract operator OIDs from the pg_constraint tuple */ datum = SysCacheGetAttrNotNull(CONSTROID, ht_constr, Anum_pg_constraint_conexclop); @@ -2305,6 +2308,7 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt) } index->nulls_not_distinct = constraint->nulls_not_distinct; index->isconstraint = true; + index->iswithoutoverlaps = constraint->without_overlaps; index->deferrable = constraint->deferrable; index->initdeferred = constraint->initdeferred; @@ -2397,6 +2401,11 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt) errmsg("index \"%s\" is not valid", index_name), parser_errposition(cxt->pstate, constraint->location))); + /* + * Today we forbid non-unique indexes, but we could permit GiST + * indexes whose last entry is a range type and use that to create a + * WITHOUT OVERLAPS constraint (i.e. a temporal constraint). + */ if (!index_form->indisunique) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), @@ -2673,6 +2682,23 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt) notnullcmds = lappend(notnullcmds, notnullcmd); } } + + if (constraint->without_overlaps) + { + /* + * This enforces that there is at least one equality column + * besides the WITHOUT OVERLAPS columns. This is per SQL + * standard. XXX Do we need this? + */ + if (list_length(constraint->keys) < 2) + ereport(ERROR, + errcode(ERRCODE_SYNTAX_ERROR), + errmsg("constraint using WITHOUT OVERLAPS needs at least two columns")); + + /* WITHOUT OVERLAPS requires a GiST index */ + index->accessMethod = "gist"; + } + } /* |