Collected from the PG bugs email list.
|OS||Windows 10 64 bit, Linux|
|Reported by||Michael Dobrovnik|
Body of first available message related to this bug follows.
The following bug has been logged on the website: Bug reference: 15787 Logged by: Michael Dobrovnik Email address: (redacted) PostgreSQL version: 11.2 Operating system: Windows 10 64 bit, Linux Description: Hello, we are using a BYTEA column to store the contents of (large) files and retrieve them later on. On a particular customer system, we were getting memory allocation errors which were not a pain to reproduce in our systems. After much ado, we can finally pin it down to a logging configuration. The problematic system had log_min_duration=x configured. So: On PostgreSQL 11.2 (and 10.6. and 9.6.12 and 9.6.8) one gets memory alloc errors when the statement is logged (triggered e.g. via log_min_duration=x or via log_statement=all in postgresql.conf). c.f. postgresql.log: 2019-04-30 09:51:52 CEST testdb test100 ERROR: invalid memory alloc request size 1846358165 2019-04-30 09:51:52 CEST testdb test100 STATEMENT: update doccontent set content = $1 where oid=$2 the operation fails due to logging. Without logging the operation succeeds. Logging tries to write the parameters of the statement, the bytea column is written out in hex format, as can be seen in the following line (for a smaller file) 2019-04-30 10:48:41 CEST testdb test100 DETAIL: parameters: $1 = '\x504b0304140000000.... so the allocation size 1846358165 comes from a file that is about 923179081 bytes in length (plus /minus preamble and trailer) A warning in the documentation of the logging parameters will definitely be helpful. A more robust solution could e.g. be to truncate the bytea values written to the log at some sensible (configurable) length (and also to read them just up to that length for logging). thank you all for your efforts concering PostgreSQL! kind regards Michael Dobrovnik
|2019-04-30 10:27:18+00||PG Bug reporting form||BUG #15787: Statement logging may consume huge amounts of memory when BYTEA parameters are involved.|