To implement a unique constraint in PostgreSQL when NULL conflicts with everything, you can use the following method: Use the COALESCE function to replace any NULL values in the new column with a unique value, […]
How is checkpointing implemented in MySQL and PostgreSQL? Checkpointing is a process that is used to periodically write dirty pages from the buffer pool to disk in order to free up memory and reduce the […]
How to control automatic database maintenance operations in PostgreSQL 15? In PostgreSQL 15, automatic database maintenance is controlled by several configuration parameters. Here are a few examples: maintenance_work_mem – this parameter controls the amount of […]
How is the transaction model implemented in PostgreSQL? In PostgreSQL, transactions are implemented using the Multi-Version Concurrency Control (MVCC) model. This means that each transaction is given a snapshot of the database at the start […]
How to check which queries are active or blocked in PostgreSQL? You can use the pg_stat_activity view in PostgreSQL to check which queries are currently active or blocked. This view provides information about each running […]
How PostgreSQL Locking works with FOR UPDATE MODE queries? In PostgreSQL, when a query is executed with the FOR UPDATE mode, it places a lock on the selected rows. This lock prevents any other queries […]
How to handle NULL values in PostgreSQL IS NULL: This operator is used to check if a column or expression is NULL. Example: SELECT * FROM table WHERE column_name IS NULL; IS NOT NULL: This […]
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