You created a GiST index on a text column using gist_trgm_ops, but your similarity search is slow. What is a likely cause?

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PostgreSQL - Indexing Strategies

You created a GiST index on a text column using gist_trgm_ops, but your similarity search is slow. What is a likely cause?

AThe column data type is <code>integer</code>

BThe <code>pg_trgm</code> extension is not installed

CThe index was created with B-tree instead of GiST

DThe table has no rows

Step-by-Step Solution

Solution:

Step 1: Check extension requirements
The gist_trgm_ops operator class requires the pg_trgm extension to be installed for trigram indexing.
Step 2: Analyze other options
Integer data type is incompatible with trigram ops, but question states text column. B-tree index would cause different issues. Empty table would not cause slowness.
Final Answer:
The pg_trgm extension is not installed -> Option B
Quick Check:
pg_trgm extension missing = slow trigram search [OK]

Quick Trick: Install pg_trgm extension for gist_trgm_ops [OK]

Common Mistakes:

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