[Dovecot] When are search indexes updated?

[Timo Sirainen]

On 28.10.2012, at 4.46, Stan Hoeppner wrote:

>> * When are search indexes updated?
> 
> When the index is stale.
> 
>> * Are they updated incrementally?
>> * If not, why not?
>> * If so, why would a mailbox's index drift out-of-date, as mine had?
> 
> When a sufficient number of messages are added to an IMAP folder the FTS
> index becomes stale.  This index is not updated in real time.  This is
> why Timo and others recommend cron'ing a script to index folders
> regularly that are searched regularly.  This keeps the indexes up to
> date and keeps searches fast.  If you don't do this or search often,
> your indexes become stale.  Then each time you do an FTS search the
> first thing that happens is an FTS re-indexing of the mail folder.  Only
> then does it display the search results.

Otherwise correct, but "re-indexing" is the wrong word. No already indexed mails are reindexed. Only new mails are added to the index.