Index Scan

Uses an index to identify table tuples and fetches them from the relation.

Reading PG 18·Select a recorded version

Core node tag: T_IndexScan
Structured EXPLAIN Node Type: Index Scan
Inputs: An index and its relation
Output: Qualified table tuples
Executor initializer: ExecInitIndexScan
Memory mechanism: unclassified
evidence kind: source and documentation
explain names: Index Scan
explain prefixes: Parallel, Async
node tag: T_IndexScan
parallel callbacks: ExecIndexScanEstimate, ExecIndexScanInitializeDSM, ExecIndexScanInitializeWorker, ExecIndexScanReInitializeDSM, ExecIndexScanRetrieveInstrumentation
partial modes: Unknown
runtime verified: false
strategies: Unknown

Definition PG 18

Uses an index to identify table tuples and fetches them from the relation.

EXPLAIN labels in this source build

Text-format label	Structured node identity
Index Scan	Index Scan

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Complete source facts

memory

{"description":"This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.","evidence":[{"archive_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","label":"src/backend/executor/nodeIndexscan.c","path":"src/backend/executor/nodeIndexscan.c","sha256":"7bd7ad26dc403544b67a5b151cb28157f135e87733e78204c8b279f2ceb8f4dc","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"}],"mechanism":"unclassified","source_notes":["If the index was lossy, we have to recheck the index quals using the fetched tuple.","If the index was lossy, we have to recheck the index quals and ORDER BY expressions using the fetched tuple."]}

source inventory

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

Source references

Full definition and evidence JSON

Definition sources

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f

Text language: en · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f