I know I visited current/limits.html many times (mostly for things like "max field length")
However, I was really surprised there's an easy to hit limit on the number of expressions in SELECT.
I don't ask to lift the limit, however, I am sure documenting the limit would make it clear
for the application developers that the limit exists and they should plan for it in advance.
----
I bumped into "target lists can have at most 1664 entries" when I was trying to execute a statement with 65535 parameters.
I know wire format uses unsigned int2 for the number of parameters, so I wanted to test if the driver supports that.
a) My first test was like select ? c1, ? c2, ? c3, ..., ? c65535
Then it failed with "ERROR: target lists can have at most 1664 entries".
I do not think "columns per table" is applicable to select like that
b) Then I tried select ?||?||?||?||....||?
I wanted to verify that the driver sent all the values properly, so I don't want to just ignore them and I concatenated the values.
Unfortunately, it failed with "stack depth limit exceeded. Increase the configuration parameter "max_stack_depth" (currently 2048kB), after ensuring the platform's stack depth limit is adequate"
Finally, I settled on select ARRAY[?, ?, ... ?] which worked up to 65535 parameters just fine.
Please, do not suggest me avoid 65535 parameters. What I wanted was just to test that the driver was able to handle 65535 parameters.
