Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Tom Lane
Glen Parker <[EMAIL PROTECTED]> writes: > How can I determine the default storage type for a given TOASTable > data type (text in this case)? Look in pg_type ... but they mostly default to "extended". regards, tom lane ---(end of broadcast)

Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Glen Parker
Tom Lane wrote: Glen Parker <[EMAIL PROTECTED]> writes: How much of a TOAST'd field is actually stored in the main heap table? Is there a way to configure that amount? A pushed-out-of-line value is replaced by a 20-byte pointer structure. There's no such thing as partially out-of-line. See ht

Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Tom Lane
Glen Parker <[EMAIL PROTECTED]> writes: > How much of a TOAST'd field is actually stored in the main heap table? > Is there a way to configure that amount? A pushed-out-of-line value is replaced by a 20-byte pointer structure. There's no such thing as partially out-of-line. See http://www.postgr

Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Alan Hodgson
On Thursday 26 October 2006 12:51, Glen Parker <[EMAIL PROTECTED]> wrote: > Why would very large text values effect the speed of a seq scan that > does not actually evaluate those values? Seq scan reads the whole table. The limiting factor is the size of the table on disk. -- "If a nation expe

Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Glen Parker
Tom Lane wrote: Glen Parker <[EMAIL PROTECTED]> writes: Why would very large text values effect the speed of a seq scan that does not actually evaluate those values? I'd actually suppose it's the smaller values (up to a few hundred bytes) that impact this the most. Really wide fields would be

Re: [GENERAL] Effect of large text field data on queries

2006-10-26 Thread Tom Lane
Glen Parker <[EMAIL PROTECTED]> writes: > Why would very large text values effect the speed of a seq scan that > does not actually evaluate those values? More bytes to scan over? Have you checked the physical table sizes? I'd actually suppose it's the smaller values (up to a few hundred bytes)