1) 0001-Rewrite-hash-index-scans-to-work-a-page-at-a-time.patch: this patch rewrites the hash index scan module to work in page-at-a-time mode. It basically introduces two new functions-- _hash_readpage() and _hash_saveitem(). The former is used to load all the qualifying tuples from a target bucket or overflow page into an items array. The latter one is used by _hash_readpage to save all the qualifying tuples found in a page into an items array. Apart from that, this patch bascially cleans _hash_first(), _hash_next and hashgettuple().
I see that forward and backward scan cases of function _hash_readpage contain a lot of code duplication
Could you please refactor this function to have less code duplication?
Also, I wonder if you have a special idea behind inserting data in test.sql by 1002 separate SQL statements.
INSERT INTO con_hash_index_table (keycol) SELECT a FROM GENERATE_SERIES(1, 1000) a;
You can achieve the same result by execution of single SQL statement.
INSERT INTO con_hash_index_table (keycol) SELECT (a - 1) % 1000 + 1 FROM GENERATE_SERIES(1, 1002000) a;
Unless you have some special idea of doing this in 1002 separate transactions.
------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
