All you are saying disproves following: in experiment I replaces bigint index: CREATE INDEX ix_t_big ON test.t USING btree (id_big) TABLESPACE tblsp_ix; with 4 (!) other indexes: CREATE INDEX ix_t2 ON test.t USING btree (ip) TABLESPACE tblsp_ix; CREATE INDEX ix_t3 ON test.t USING btree (id_small) TABLESPACE tblsp_ix; CREATE INDEX ix_t4 ON test.t USING btree (id_smalll) TABLESPACE tblsp_ix; CREATE INDEX ix_t5 ON test.t USING btree (ts) TABLESPACE tblsp_ix; which are definitely larger then one bigint index. 0.000u 0.005s 0:13.23 0.0% 0+0k 0+0io 0pf+0w COPY 100000 0.000u 0.035s 0:05.08 0.5% 421+1114k 0+0io 0pf+0w COPY 100000 0.000u 0.036s 0:19.28 0.1% 526+1393k 0+0io 0pf+0w COPY 100000 0.000u 0.005s 0:05.56 0.0% 0+0k 0+0io 0pf+0w COPY 100000 0.006u 0.012s 0:05.57 0.1% 984+1820k 0+0io 0pf+0w COPY 100000 0.007u 0.029s 0:05.20 0.3% 808+1746k 0+0io 0pf+0w COPY 100000 0.005u 0.000s 0:05.35 0.0% 0+0k 0+0io 0pf+0w COPY 100000 0.000u 0.011s 0:05.92 0.1% 316+836k 0+0io 0pf+0w COPY 100000 0.000u 0.005s 0:12.08 0.0% 0+0k 0+0io 0pf+0w COPY 100000 0.000u 0.029s 0:05.46 0.3% 808+2074k 0+0io 0pf+0w COPY 100000 0.002u 0.002s 0:05.35 0.0% 0+0k 0+0io 0pf+0w COPY 100000 0.000u 0.005s 0:06.52 0.0% 0+0k 0+0io 0pf+0w Insertions became slower 4-5 times, which is ok. Nothing is closer to even half of minute, while one bigint index constantly gives more then minute and even 2 for 100k records. On Thu, Aug 4, 2011 at 8:22 PM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > Robert Ayrapetyan <robert.ayrapetyan@xxxxxxxxxx> wrote: > >> If you look at the rest of my mail - you would notice 50 times >> difference in performance. >> What you would say? > > That accessing a page from RAM is more than 50 times as fast as a > random access of that page from disk. > > -Kevin > -- Ayrapetyan Robert, Comodo Anti-Malware Data Processing Analysis and Management System (CAMDPAMS) http://repo-qa.camdpams.odessa.office.comodo.net/mediawiki/index.php -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
