Meilisearch v1.38 removes full DB scans during vector indexing

Prior to v1.38, vector indexing performed full database scans to retrieve item IDs, fetch item pointers, and fetch link pointers, consuming hundreds of seconds. The traces 'retrieving the items ids' (459s), 'fetch item pointers' (4.92s), and 'fetch links pointers' (168s) dominated indexing time alongside 'writing the items' (428s).

Upgrade to Meilisearch v1.38 or later. This version eliminates most full DB scans by fetching items lazily and uses a forked LMDB version that allows reading uncommitted write transaction content from multiple read transactions in parallel. Monitor indexing traces to verify that 'retrieving the items ids', 'fetch item pointers', and 'fetch links pointers' traces are significantly reduced or eliminated.