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Use multi-inserts for pg_attribute and pg_shdepend

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For pg_attribute, this allows to insert at once a full set of attributes
for a relation (roughly 15% of WAL reduction in extreme cases).  For
pg_shdepend, this reduces the work done when creating new shared
dependencies from a database template.  The number of slots used for the
insertion is capped at 64kB of data inserted for both, depending on the
number of items to insert and the length of the rows involved.

More can be done for other catalogs, like pg_depend.  This part requires
a different approach as the number of slots to use depends also on the
number of entries discarded as pinned dependencies.  This is also
related to the rework or dependency handling for ALTER TABLE and CREATE
TABLE, mainly.

Author: Daniel Gustafsson
Reviewed-by: Andres Freund, Michael Paquier
Discussion: https://postgr.es/m/20190213182737.mxn6hkdxwrzgxk35@alap3.anarazel.de
This commit is contained in:
Michael Paquier
2020-07-31 10:54:26 +09:00
parent cab2556f3a
commit e3931d01f3
8 changed files with 223 additions and 117 deletions
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8
src/backend/commands/tablecmds.c
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@@ -5975,6 +5975,8 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
AlterTableCmd *childcmd;
AclResult aclresult;
ObjectAddress address;
TupleDesc tupdesc;
FormData_pg_attribute *aattr[] = {&attribute};
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
@@ -6128,11 +6130,13 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
attribute.attislocal = colDef->is_local;
attribute.attinhcount = colDef->inhcount;
attribute.attcollation = collOid;
/* attribute.attacl is handled by InsertPgAttributeTuple */
/* attribute.attacl is handled by InsertPgAttributeTuples() */
ReleaseSysCache(typeTuple);
InsertPgAttributeTuple(attrdesc, &attribute, (Datum) 0, NULL);
tupdesc = CreateTupleDesc(lengthof(aattr), (FormData_pg_attribute **) &aattr);
InsertPgAttributeTuples(attrdesc, tupdesc, myrelid, NULL, NULL);
table_close(attrdesc, RowExclusiveLock);