On 16/12/10 12:28, Werner Scholtes wrote:
Thanks a lot for your advice. I found the difference: My Java program sends one huge SQL string containing 1000 INSERT statements separated by ';' (without using prepared statements at all!), whereas my C++ program sends one INSERT statement with parameters to be prepared and after that 1000 times parameters. Now I refactured my C++ program to send also 1000 INSERT statements in one call to PQexec and reached the same performance as my Java program.
So - it was the network round-trip overhead. Like Divakar suggested, COPY or VALUES (),(),() would work too.
You mention multiple updates/deletes too. Perhaps the cleanest and fastest method would be to build a TEMP table containing IDs/values required and join against that for your updates/deletes.
I just wonder why anyone should use prepared statements at all?
Not everything is a simple INSERT. Preparing saves planning-time on repeated SELECTs. It also provides some SQL injection safety since you provide parameters rather than building a SQL string.
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