From 579ad14d7c4521754c9942ac39b39b6110338923 Mon Sep 17 00:00:00 2001 From: Hallvard Furuseth Date: Thu, 28 May 2015 20:51:24 +0200 Subject: [PATCH] ITS#8156 Fix MDB_MAXKEYSIZE doc --- libraries/liblmdb/mdb.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c index 612cd0c..482b98e 100644 --- a/libraries/liblmdb/mdb.c +++ b/libraries/liblmdb/mdb.c @@ -510,12 +510,17 @@ static txnid_t mdb_debug_start; /** The version number for a database's lockfile format. */ #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1) - /** @brief The max size of a key we can write, or 0 for dynamic max. + /** @brief The max size of a key we can write, or 0 for computed max. * - * Define this as 0 to compute the max from the page size. 511 - * is default for backwards compat: liblmdb <= 0.9.10 can break - * when modifying a DB with keys/dupsort data bigger than its max. - * #MDB_DEVEL sets the default to 0. + * This macro should normally be left alone or set to 0. + * Note that a database with big keys or dupsort data cannot be + * reliably modified by a liblmdb which uses a smaller max. + * The default is 511 for backwards compat, or 0 when #MDB_DEVEL. + * + * Other values are allowed, for backwards compat. However: + * A value bigger than the computed max can break if you do not + * know what you are doing, and liblmdb <= 0.9.10 can break when + * modifying a DB with keys/dupsort data bigger than its max. * * Data items in an #MDB_DUPSORT database are also limited to * this size, since they're actually keys of a sub-DB. Keys and