Re:Lightning Memory-Mapped Database Manager (LMDB) 1.0
by hyc_symas on Friday July 03, 2026 @11:18AM
(#48776081)
LMDB 1.0 no longer uses a P_DIRTY flag, it no longer has to explicitly mark pages as clean.
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Re:Lightning Memory-Mapped Database Manager (LMDB) 1.0
by keynha on Sunday July 05, 2026 @02:44AM
(#48791822)
Dropping the explicit P_DIRTY flag in 1.0 is a neat change. What tracks which pages still need to be written back at commit now that the flag is gone?
Re:Lightning Memory-Mapped Database Manager (LMDB) 1.0
by hyc_symas on Sunday July 05, 2026 @10:32AM
(#48794579)
The txnID was added to the page header to enable support for incremental backup. As a consequence, it's sufficient to compare a page's txnID to the current txnID to know if it's dirty or not, and spilled pages don't need a cleanup pass to clear their dirty bit on commit so commits of large txns are faster now.