Thank you.
Removing substring and revuilding the indexes worked.
The size iscnow similar to lucene, and approx 8x smaller than with substring emabled.
Speed also seems 20%-30% faster when querying the text or body of email.
Thank you for the help.
On Thu, May 14, 2026, 4:45 p.m. Aki Tuomi <aki.tuomi@open-xchange.com> wrote:
On 14/05/2026 23:21 EEST Jean-Daniel Beaubien via dovecot < dovecot@dovecot.org> wrote:
Hi everyone,
I am currently trying to update from an old dovecot 2.3 setup with fts-lucene to 2.4.2 with fts-flatcurve.
However, I am seeing a giant jump in the size of the indexes.
For an email account that takes 12GB of storage, I get the following index sizes:
- lucene: 270 MB
- flatcurve: 2400 MB
That is almost a 10x increase in the index size (with flatcurve the indexes represent 20% of the size of the mailbox).
Hi!
You have substring search enabled, that will incur a larger size as those substrings need to be indexed somewhere.
Aki
Thank you. Removing substring and revuilding the indexes worked. The size iscnow similar to lucene, and approx 8x smaller than with substring emabled. Speed also seems 20%-30% faster when querying the text or body of email. Thank you for the help. On Thu, May 14, 2026, 4:45p.m. Aki Tuomi <[1]aki.tuomi@open-xchange.com> wrote:
> On 14/05/2026 23:21 EEST Jean-Daniel Beaubien via dovecot
<[2]dovecot@dovecot.org> wrote:
>
>
> Hi everyone,
>
> I am currently trying to update from an old dovecot 2.3 setup with
> fts-lucene to 2.4.2 with fts-flatcurve.
>
> However, I am seeing a giant jump in the size of the indexes.
>
> For an email account that takes 12GB of storage, I get the following
index
> sizes:
>
> - lucene: 270 MB
> - flatcurve: 2400 MB
>
>
> That is almost a 10x increase in the index size (with flatcurve the
indexes
> represent 20% of the size of the mailbox).
Hi!
You have substring search enabled, that will incur a larger size as
those substrings need to be indexed somewhere.
AkiReferences
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