On 2013-04-19 13:57, Stuart Broad wrote:
Hi,
I am using Cassandra.Client
prepare_cql3_query/execute_prepared_cql3_query to create and run some
prepared statements. It is working well but I am unclear as to how long
the server side 'caches' the prepared statements. Should a prepared
statement be prepared for every new Cassandra.Client? Based on my
limited testing it seems like I can create some prepared statements in
one Cassandra.Client and use in another but I am not sure how
reliable/lasting this is i.e. If I called the prepared statement again
the next day would it still exist? What about if cassandra was re-started?
_Background:_
I am creating prepared statements for batch updates of pre-defined
lengths (e.g. 10000, 1000, 500, 250, 50, 10, 1) and wanted to know if
these could just be set up once. We felt that using the prepared
statements was easier than escaping values within a CQL statement and
probably more performant.
Thanks in advance for your help.
I've looked in Cassandra's code (v1.2.3). The cache of prepared
statements has a size of 100,000. So if you prepare more than 100
thousand statements, the least recently used ones will vanish. You'll
get the exception PreparedQueryNotFoundException, code 0x2500.
Regards,
Sorin
