Re: Saving stack space in nbtree's _bt_first function

Hi,

However, there's no reason why "ScanKeyData
notnullkeys[INDEX_MAX_KEYS]" needs to be an array at all. In practice,
_bt_first will only need a single temp notnullkeys ScanKeyData, since
there can never be more than a single deduced NOT NULL constraint used
within our final insertion scan key.

As an experiment, I added an elog(WARNING,...) just above the main changed line in the patch, and then ran the tests (make installcheck). This resulted in lines logged next to some of the SELECT statements in the following files in src/test/regress/sql: 

• create_index.sql
• inherit.sql

I saw the log line only once per query, showing that at least for the scenarios in the tests, the claim checks out. I then tried a couple of modifications to those queries which generated the log line, but did not get it to log more than once. 

Kind regards,

Mircea Cadariu