Hi Dilip, v6 patch: 42 + /* 43 + * Estimate number of hashtable entries we can have within maxbytes. This 44 + * estimates the hash cost as sizeof(PagetableEntry). 45 + */ 46 + nbuckets = maxbytes / 47 + (sizeof(PagetableEntry) + sizeof(Pointer) + sizeof(Pointer));
It took me a little while to understand this calculation. You have moved this code from tbm_create(), but I think you should move the following comment as well: tidbitmap.c: 276 /* 277 * Estimate number of hashtable entries we can have within maxbytes. This 278 * estimates the hash cost as sizeof(PagetableEntry), which is good enough 279 * for our purpose. Also count an extra Pointer per entry for the arrays 280 * created during iteration readout. 281 */ Regards, Amul -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
