X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=Documentation%2Fpublic-inbox-v2-format.pod;h=d6282cb4b884b783ed939307f7be2ff3a7bf2e8b;hb=734daa9b165e248c1f5d6a0c4689a5c1372fc846;hp=9e284a754313d654ccce23dc685ecca564e34922;hpb=098fecd1fe516a00fbfd49622b82be382ebcdab6;p=public-inbox.git diff --git a/Documentation/public-inbox-v2-format.pod b/Documentation/public-inbox-v2-format.pod index 9e284a75..d6282cb4 100644 --- a/Documentation/public-inbox-v2-format.pod +++ b/Documentation/public-inbox-v2-format.pod @@ -113,9 +113,14 @@ improved with high-quality and high-quantity solid-state storage. Issuing TRIM commands with L was necessary to maintain consistent performance while developing this feature. -Rotational storage devices are NOT recommended for indexing of -large mail archives; but are fine for backup and usable for -small instances. +Rotational storage devices perform significantly worse than +solid state storage for indexing of large mail archives; but are +fine for backup and usable for small instances. + +As of public-inbox 1.6.0, the C +option of L may be used with a high shard +count to ensure individual shards fit into page cache when the entire +Xapian DB cannot. Our use of the L requires Xapian document IDs to remain stable. Using L and @@ -133,7 +138,7 @@ OVER/XOVER commands). The overview DB maintains all the header information necessary to implement the NNTP OVER/XOVER commands and non-search -endpoints of of the PSGI UI. +endpoints of the PSGI UI. Xapian has become completely optional for v2 (as it is for v1), but SQLite remains required for v2. SQLite turns out to be powerful