database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-08 11:42:09 +03:00
Code Activity

Speed up COPY into tables with DEFAULT nextval()

Browse Source 
Previously the presence of a nextval() prevented the
use of batch-mode COPY.  This patch introduces a
special case just for nextval() functions. In future
we will introduce a general case solution for
labelling volatile functions as safe for use.
This commit is contained in:
Simon Riggs
2014-01-20 17:22:38 +00:00
parent 74a72ec208
commit 4d1e2aeb1a
3 changed files with 130 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
src/backend/commands/copy.c
View File

@ -2519,9 +2519,20 @@ BeginCopyFrom(Relation rel,
defmap[num_defaults] = attnum - 1;
num_defaults++;
/* Check to see if we have any volatile expressions */
/*
* If a default expression looks at the table being loaded, then
* it could give the wrong answer when using multi-insert. Since
* database access can be dynamic this is hard to test for
* exactly, so we use the much wider test of whether the
* default expression is volatile. We allow for the special case
* of when the default expression is the nextval() of a sequence
* which in this specific case is known to be safe for use with
* the multi-insert optimisation. Hence we use this special case
* function checker rather than the standard check for
* contain_volatile_functions().
*/
if (!volatile_defexprs)
volatile_defexprs = contain_volatile_functions((Node *) defexpr);
volatile_defexprs = contain_volatile_functions_not_nextval((Node *)defexpr);
}
}
}