Bitmap Index Scan

Scans an index and produces a bitmap of matching tuple locations.

Reading PG 18·Select a recorded version

Core node tag: T_BitmapIndexScan
Structured EXPLAIN Node Type: Bitmap Index Scan
Inputs: An index
Output: Tuple-location bitmap, not a tuple stream
Executor initializer: ExecInitBitmapIndexScan
Memory mechanism: bitmap-lossification
evidence kind: source and documentation
explain names: Bitmap Index Scan
explain prefixes: Parallel, Async
node tag: T_BitmapIndexScan
parallel callbacks: ExecBitmapIndexScanEstimate, ExecBitmapIndexScanInitializeDSM, ExecBitmapIndexScanInitializeWorker, ExecBitmapIndexScanRetrieveInstrumentation
partial modes: Unknown
runtime verified: false
strategies: Unknown

Definition PG 18

Scans an index and produces a bitmap of matching tuple locations.

EXPLAIN labels in this source build

Text-format label	Structured node identity
Bitmap Index Scan	Bitmap Index Scan

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Complete source facts

memory

{"description":"The node allocates a tuple-location bitmap using a work_mem-derived budget. A bitmap can retain page-level lossy entries instead of every tuple location; heap rechecks then remain necessary.","evidence":[{"archive_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","label":"src/backend/executor/nodeBitmapIndexscan.c","path":"src/backend/executor/nodeBitmapIndexscan.c","sha256":"7eed6439851a24333252fcce6e7c71856e8da9bdaee78597401b11afdbb093c0","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"archive_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","label":"src/backend/nodes/tidbitmap.c","path":"src/backend/nodes/tidbitmap.c","sha256":"e2453b7155d55db8c3a59bc929362f01d3f9692b0a483e5aa81a7b6c50db6102","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"}],"mechanism":"bitmap-lossification","source_notes":[]}

source inventory

{"executor":"src/backend/executor/execProcnode.c","explain":"src/backend/commands/explain.c","implementation":"src/backend/executor/nodeBitmapIndexscan.c"}

Source references

Full definition and evidence JSON

Definition sources

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f

Text language: en · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f