Summary:
db_bench had no way to exercise SST embedded (same-file) blob reads or wide-column entity reads (GetEntity/MultiGetEntity), which are needed to measure the zero-copy embedded-blob wide-column entity read path.
This adds:
- Two setup benchmarks, fillembeddedentity and fillembeddedblob, that build an SST via SstFileWriter::OpenWithEmbeddedBlobs and ingest it (embedded blobs can only be produced this way, not by fillrandom/flush/compaction). Entity mode writes wide-column entities whose large columns are embedded blobs; blob mode writes whole-value embedded blobs. Both require format_version >= 7.
- readrandomentity (GetEntity) and multireadentity (MultiGetEntity) read benchmarks; plain readrandom is reused for the whole-value embedded blob baseline and for entity default-column Get.
- Flags embedded_blob_min_size, num_wide_columns, and num_short_wide_columns to control the embedded threshold and the inline/embedded column mix per entity.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14995
Test Plan: Manual db_bench runs of the new benchmarks, used to validate D113347622.
Reviewed By: xingbowang
Differential Revision: D113455538
Pulled By: pdillinger
fbshipit-source-id: c6b62f5a2d6a61ae0b7cc32ac1b445b566ea8842
0347b4df61