Re: UPDATE STATISTICS

Posted in 2003

Mark Denham — Thu, 21 Aug 2003 22:43:38 -0400 — source: Usenet: comp.databases.informix

Updates statistics for each column in the table. If your version is older than 7.31UD2 or 9.30 [not certain for 9] I think you will find that the table is read multiple times, once for each col in the table. This would explain the astronomical increase in the runtime. Mark ----- Original Message ----- From: "Thomas J. Girsch" <tgirsch@worldnet.att.net> To: <informix-list@iiug.org> Sent: Thursday, August 21, 2003 21:12 Subject: UPDATE STATISTICS > Imagine a table tab1 with a bazillion rows and five columns. There is one > index on the table, on column A. > > If I do: > > UPDATE STATISTICS LOW FOR TABLE tab1(col_a);> > ... it runs very quickly. But if I just do: > > UPDATE STATISTICS LOW FOR TABLE tab1;> > ... it takes hours, maybe days. So what exactly does the latter command do, > that the former command does NOT do? > > sending to informix-list