SQL: Table corrupted

Symptoms : SQL cannot select, insert or update data .

Impact : Critical

Data cannot be selected from or inserted into one or more tables causing loss of data to the application.

Expected behavior :

This alert indicates unexpected behavior and needs to be investigated.

Possible causes

IO subsystem level problem  Priority : Critical
Failure of some hardware component handling data traffic or storage is the most likely reason for this error. The elements involved are:

  • Drives
  • Controllers
  • Incorrect Drivers

Recommended action :
Firstly, identify the faulty component and repair/replace. Next, perform database integrity checks:

  • Run SQL DBCC checkdb
  • Run Disk-Check utility

  • In case of damage or loss of integrity, locate most recent database backup and restore the table with assistance of DB Admin.

Background

Corruption of one or more tables will strongly affect functionality and avaiability. Building levels of redundancy (clustered servers, cloud-based infrastructures etc.) will minimize impact, but to only sure way to guarantee full recovery in the shortest possible time is to maintain comprehensive up-to-date backup routines.