Answer
CREATE INDEX CONCURRENTLY builds indexes without blocking writes, though it takes longer to complete.
Quick Answer
CREATE INDEX CONCURRENTLY builds an index without taking a lock that blocks writes. Regular CREATE INDEX locks the table for reads and writes during build. CONCURRENTLY: takes longer (two table scans), can't run inside a transaction block. May fail if the table has long-running transactions when the index build starts. Best practice for production: always use CONCURRENTLY for new indexes on live tables.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
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Source: SugharaIQ