Bumping it to attract some attention. On Tue, Mar 21, 2023 at 12:51 PM Ashutosh Bapat <ashutosh.bapat....@gmail.com> wrote: > > Hi, > Hash table scans (seq_scan_table/level) are cleaned up at the end of a > transaction in AtEOXact_HashTables(). If a hash seq scan continues > beyond transaction end it will meet "ERROR: no hash_seq_search scan > for hash table" in deregister_seq_scan(). That seems like a limiting > the hash table usage. > > Our use case is > 1. Add/update/remove entries in hash table > 2. Scan the existing entries and perform one transaction per entry > 3. Close scan > > repeat above steps in an infinite loop. Note that we do not > add/modify/delete entries in step 2. We can't use linked lists since > the entries need to be updated or deleted using hash keys. Because the > hash seq scan is cleaned up at the end of the transaction, we > encounter error in the 3rd step. I don't see that the actual hash > table scan depends upon the seq_scan_table/level[] which is cleaned up > at the end of the transaction. > > I have following questions > 1. Is there a way to avoid cleaning up seq_scan_table/level() when the > transaction ends? > 2. Is there a way that we can use hash table implementation in > PostgreSQL code for our purpose? > > > -- > Best Wishes, > Ashutosh Bapat
-- Best Wishes, Ashutosh Bapat
