Hello PG hackers. Yesterday I began diagnosing a peculiar bug in some production code that has been happily running for months. I finally got to the bottom of it despite the rather misleading error message. Anyway, within a section of code we are making a DELETE call to the database via the libpq call PQexecParams(). It failed with this message:
'ERROR: bind message has 32015 parameter formats but 1 parameters'
This was just plain wrong. In fact, the # of parameters was more like 80,000. The area of code is quite clear. Despite this being a particularly large number of parameters (as you can imagine this query is built dynamically based on arbitrarily sized input) the data type for nParams for is a plain old 4-byte int. Upon further and deeper inspection I find that this 4 byte int is truncated to two bytes just before going down the wire.
There is no mention of any restriction in the 9.1.4 documentation:
And the interface quite clearly accepts a 4 byte int however, the PQsendQueryGuts() function on line 1240 of src/interfaces/libpq/fq-exec.c just blatantly truncates the integer - it's calls pqPutInt() for nParams with a literal 2 rather than 4. It does this several times, in fact.
Unless I'm barking mad, surely this should either
a) Be fixed and send 4 with nParams for pqPutInt() rather than 2 b) Documented (and the type changed) as only being a 2 byte int and therefore having a restriction on the number of parameters permitted in PQexecParams().
Could someone either verify or correct me before I submit an official bug report!?
