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authorPeter Eisentraut <peter@eisentraut.org>2019-03-30 08:13:09 +0100
committerPeter Eisentraut <peter@eisentraut.org>2019-03-30 08:15:57 +0100
commitfc22b6623b6b3bab3cb057ccd282c2bfad1a0b30 (patch)
treecda5092955ece5d547d5517ed56a3d480f199d25 /src/backend/parser/parse_relation.c
parent6b8b5364ddd0e4d882562615c6b6c28638ade9f2 (diff)
downloadpostgresql-fc22b6623b6b3bab3cb057ccd282c2bfad1a0b30.tar.gz
Generated columns
This is an SQL-standard feature that allows creating columns that are computed from expressions rather than assigned, similar to a view or materialized view but on a column basis. This implements one kind of generated column: stored (computed on write). Another kind, virtual (computed on read), is planned for the future, and some room is left for it. Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com
Diffstat (limited to 'src/backend/parser/parse_relation.c')
-rw-r--r--src/backend/parser/parse_relation.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index f3b6d193aa..0640d11fac 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -731,6 +731,17 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, const char *colname,
colname),
parser_errposition(pstate, location)));
+ /*
+ * In generated column, no system column is allowed except tableOid.
+ */
+ if (pstate->p_expr_kind == EXPR_KIND_GENERATED_COLUMN &&
+ attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+ errmsg("cannot use system column \"%s\" in column generation expression",
+ colname),
+ parser_errposition(pstate, location)));
+
if (attnum != InvalidAttrNumber)
{
/* now check to see if column actually is defined */
@@ -1257,6 +1268,7 @@ addRangeTableEntry(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1328,6 +1340,7 @@ addRangeTableEntryForRelation(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1407,6 +1420,7 @@ addRangeTableEntryForSubquery(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1670,6 +1684,7 @@ addRangeTableEntryForFunction(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1733,6 +1748,7 @@ addRangeTableEntryForTableFunc(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1811,6 +1827,7 @@ addRangeTableEntryForValues(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1881,6 +1898,7 @@ addRangeTableEntryForJoin(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list
@@ -1983,6 +2001,7 @@ addRangeTableEntryForCTE(ParseState *pstate,
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
+ rte->extraUpdatedCols = NULL;
/*
* Add completed RTE to pstate's range table list, but not to join list