From 58054de2d0847c09ef091956f72ae5e9fb9a176e Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 27 Dec 2023 15:55:46 -0500 Subject: Improve the implementation of information_schema._pg_expandarray(). This function was originally coded with a handmade expansion of the array subscripts. We can do it a little faster and far more legibly today, by using unnest() WITH ORDINALITY. While at it, let's apply the rowcount estimation support that exists for the underlying unnest() function: reduce the default ROWS estimate to 100 and attach array_unnest_support. I'm not sure that array_unnest_support can do anything useful today with the call sites that exist in information_schema, but it can't hurt, and the existing default rowcount of 1000 is surely much too high for any of these cases. The psql.sql regression script is using _pg_expandarray() as a test case for \sf+. While we could keep doing so, the new one-line function body makes a poor test case for \sf+ row-numbering, so switch it to print another information_schema function. Discussion: https://postgr.es/m/1424303.1703355485@sss.pgh.pa.us --- src/backend/utils/adt/arrayfuncs.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/backend/utils/adt/arrayfuncs.c') diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c index 631012a0f28..e783a24519d 100644 --- a/src/backend/utils/adt/arrayfuncs.c +++ b/src/backend/utils/adt/arrayfuncs.c @@ -6317,6 +6317,9 @@ array_unnest(PG_FUNCTION_ARGS) /* * Planner support function for array_unnest(anyarray) + * + * Note: this is now also used for information_schema._pg_expandarray(), + * which is simply a wrapper around array_unnest(). */ Datum array_unnest_support(PG_FUNCTION_ARGS) -- cgit v1.2.3