SQL exceptions occur where a query has been executed but cannot complete. Best practice requires that all SQL functions and calls should be properly coded with provision for possible failure via the TRY...CATCH protocol.
Occurs when sessions are blocked or when either there is heavy network traffic or network problems, or if the computer the SQL instance is hosted on is running slow
Reports log files that have grown to big and could consume all available disk space, leading to a system crash. Log file size is highly dependent on level of activity, on database backup being performed correctly and frequently.
Data cannot be selected from or inserted into one or more tables causing loss of data to the application.
One or more of the steps in the designated SQL job did not finished successfully. SQL jobs should not fail.
This alert indicates one or more abnormal access attempts have been blocked and should be investigated.
Where normal operations are interrupted and data needs to be restored, the further back in time the last backup was done, the more complicated and longer the recovery will be.
Deadlock means that two task trying to lock resource (Table or Row table) that the other task is locking , than SQL decide which task to kill.
Risk - SQL lost of data or response cause application fault.
Reports the ratio of the data pages found and read from the SQL Server buffer cache and all data page requests. Pages that are not found in the buffer cache must be read from disk
Missing full backup can cause lost of data in case of database fault , we won't be able to restore the database.
SQL Exceptions will interrupt user flow, and potentially may cause a lack of functionality and influence application performance. This can have a strong negative impact on overall system value by degrading the performance and reliability of the data.
Queries or updates that take longer than expected to execute.
SQL has detected a block, which may affect other users trying to access the same resource. Blocking occurs when one process holds a lock on a specific resource and a second one attempts to acquire a conflicting lock type on the same resource.
The designated SQL job did not finish. Needs to be investigated. A user can cancel a job when it is already executing, or prevent it from running at all, or a job may stop while executing due to some operating system intervention.
Reporting that two or more processes are competing for exclusive access to a resource but are unable to obtain it, because some other process is preventing it. The only way out of a deadlock is for one of the processes to be terminated.
A transaction is not committed and not rolled back, remains open, idle and is using resources that could have been freed up, affecting user response times and degrading performance.
If uncontrolled, log files can consume all available disk space, leading to a system crash. As well, as the log gets larger, the potential for more downtime when recovering from a disaster increases.
Page Life Expectancy (PLE) is an SQL indicator of how long (in seconds) a data file page is expected to remain in server memory. For optimal performance, data should be read from memory rather than disk.
Missing differential backup can cause lost of data in case of database fault , we won't be able to restore the database.
Missing log backup can cause lost of data in case of database fault, we won't be able to restore the database to current point in time.
Symptoms : Server is consuming high levels of CPU capacity...
Reports a shortage of memory to satisfy all program needs. Steady...
Normal behavior is for connections to remain open only for the...
Memory is the most important resource with regard to SQL Server...
Wait times during query execution can indicate bottlenecks or...