You run REFRESH MATERIALIZED VIEW CONCURRENTLY mv_data; but get an error: "ERROR: materialized view must have a unique index to refresh concurrently." What is the cause?

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PostgreSQL - Views and Materialized Views

You run REFRESH MATERIALIZED VIEW CONCURRENTLY mv_data; but get an error: "ERROR: materialized view must have a unique index to refresh concurrently." What is the cause?

AThe base tables are locked by another transaction

BThe materialized view does not have a unique index defined

CThe materialized view does not exist

DConcurrent refresh is not supported in PostgreSQL

Step-by-Step Solution

Solution:

Step 1: Analyze error message
The error states a unique index is required for concurrent refresh.
Step 2: Identify cause
The materialized view lacks a unique index, causing the error.
Final Answer:
The materialized view does not have a unique index defined -> Option B
Quick Check:
Unique index required for concurrent refresh = The materialized view does not have a unique index defined [OK]

Quick Trick: Concurrent refresh needs unique index on materialized view [OK]

Common Mistakes:

Ignoring the need for a unique index
Blaming base table locks
Assuming concurrent refresh is unsupported

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You run REFRESH MATERIALIZED VIEW CONCURRENTLY mv_data; but get an error: "ERROR: materialized view must have a unique index to refresh concurrently." What is the cause?

Step 1: Analyze error message

Step 2: Identify cause

Final Answer:

Quick Check:

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