correlating postgres LOG and DETAIL loglines

Question

We're logging slow running queries in PG (on AWS RDS) with log_min_duration_statement along with log_error_verbosity = default so we get DETAIL lines, because our app's libraries uses prepared statements under the covers. We are using log_destination = stderr -- we can't use csvlog in this case.

What we end up with though are two disparate log lines:

LOG: duration: 1680.110 ms execute <unnamed>: SELECT.... = $1
DETAIL: parameters: $1 = 'foo'

These are two distinct log lines in the log file.

Is there any combination of settings that either (a) can combine these in a single line, so we get both the LOG and the DETAIL in the same message, or (b) is there some ID that can be used to correlate these two messages together?

Answer 1

The PostgreSQL documentation on logging suggests that "...it is recommended that you log the PID or session ID using log_line_prefix so that you can link the statement message to the later duration message using the process ID or session ID."

This should allow the correlation of the LOG and DETAIL lines.