At 13:24 27/06/2005, Praveen Raja wrote:
>I'm wondering if and how the size of a table affects speed of inserts
>into it? What if the table has indexes, does that alter the answer?
Many parameters will affect the result:
- whether there are any indexes (including the primary key, unique
constraints...) to update or not
- whether there are any foreign keys from or to that table
- the size of the rows
- whether the table (or at least the bits being updated) fit in RAM or not
- whether the table has "holes" (due to former updates/deletes and vacuum)
and how they are placed
- and probably a bunch of other things...
Obviously, if you have an append-only (no updates, no deletes) table with
no indexes and no foreign keys, the size of the table should not matter
much. As soon as one of those conditions is not met table size will have an
impact, probably small as long as whatever is needed can be held in RAM, a
lot bigger once it's not the case.
Hope that helps,
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