On Oct 5, 2004, at 10:47 AM, Dann Corbit wrote:
> Create a 64 bit hash (e.g. UMAC) of the prepared statement (removing
> hardwired parameters as needed so that "SELECT Col1, col2 FROM
> Some_Table where FOO = 'BAR'" becomes "SELECT COL1, COL2 FROM
> SOME_TABLE WHERE FOO = ?", form consistent capitalization of the
> statement by capitalizing all keywords and non-quoted column names and
> then form a hash. Create a hash table of skiplists that contain the
> prepared statement and the prepared statement handle (the hash modulo
> or bitmasked with some number is the index to which skiplist to store
> the data in). Then, when you get a query, if it is not already
> prepared, prepare it and store it in the list. If you find it in the
> list just reuse it. Of course, it only works with sticky cursors.
>
> For something like TPC benchmarks, it can mean very large savings in
> time.
>
> Any time you have a storm of small, similar queries, think 'prepared
> statement'
Yes, this is how the Perl DBI works. And with Abhijit's patch, DBD::Pg
(the DBI driver for PostgreSQL) will finally be able to take advantage
of it.
Regards,
David
