How to identify unused data store index?

[A. Kong]

Hi all,

Over time I have a number of indexes in the index.yaml . Some of them may be no longer needed because over time my application ceases to make a certain query.

Is there an easy way to identify unused indexes?

Cheers

[Christian F. Howes]

I have not found a great way to do that either.  we have a mirrored test server setup that we sometimes delete indexes from and see if anything crashes.  not a great solution though....but aside from exercising all the queries that your code runs there is nothing that can detect if an index is missing.

cfh

[Nick (Cloud Platform Support)]

There are really two issues at play here: detecting which of your indexes are under-used, and detecting which indexes are absolutely not used. The first is a matter of profiling, monitoring, logging from your own side, and the second is a matter of running appcfg.py vacuum_indexes to delete any indexes which aren't explicitly mentioned in index.yaml (that is, any indexes which you didn't explicitly code for).

You could make a Feature Request in the Public Issue Tracker for something which could help with this, such as collection of statistics in the Developers Console as to how often an index gets hit in a given time period.