On 1/18/24 08:37, Jim Vanns wrote:
Hi Tom/Adrian.
I should have already stated I did begin with EXPLAIN but given they
don't easily work with (the internals) stored/procedures, it wasn't
useful in this case. Also, I keep having to terminate the statement
because it never runs to completion and produces the plan (at least in
ANALYZE VERBOSE mode anyway).
I have, however, pulled the function body code out and produced an
isolated case that can be EXPLAINED. The table in question is a
I'm guessing the function is prune_function(timestamp)?
What is the function body code?
curious one since it models a hierarchy as an adjacency list and so
the fkey reference is back to itself (to a primary key - so is an
additional index required?):
CREATE TABLE tree (
ts TIMESTAMPTZ NOT NULL
tree_id BIGINT NOT NULL,
parent_id BIGINT NULL,
--
CONSTRAINT cstr_tree_pky PRIMARY KEY (tree_id) INCLUDE (parent_id),
FOREIGN KEY (parent_id) REFERENCES tree(tree_id)
ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED
);
CREATE INDEX ON tree USING BRIN (ts);
The tree table has 95,915,630 rows.
I've not yet got a complete or reliable plan :( I have made a DB copy
and will be dropping the constraint to see what effect that has.
Cheers,
--
Adrian Klaver
adrian.kla...@aklaver.com
