Symptoms

When confluence reindex, it creates a lot of files in the confluence_install/temp folder and can easily reach Gigabytes of information after some time of confluence usage.

The picture below shows how the temp folder will become after some re-indexes.

Cause

This is caused by a bug in Confluence office connector extractor for PPTX files that doesn't clean the temporary files after reindexing them. It is stated here: CONF-33898 - Getting issue details... STATUS

Workaround

Disable the index of PPT and PPTX files for now as stated here: How to disable indexing of attachments