I currently have a table which contains a VARCHAR(20) column. The assumption that the column will contain a maximum of 20 characters has held for a long time, however recently a need has resulted for it to also contain very long strings. Is there a performance overhead on the table on (i.e inserts/deletes/selects) if I were to change the table to smalltext (or a long varchar). I never need to search on this field, just retrieve and insert it's value. If so, should I (reluctantly) introduce a separate column for the larger values?
Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.
Composite queries are used to retrieve the results from joining multiple queries after applying any filters. UNION, INTERSECT, MINUS, and UNION ALL are some of the operators used to get certain desired results.
In this article we will get to know that how can we recover deleted data if it happens accidently. We really can recover deleted rows if we know the time when data is deleted by using the transaction log.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables.
Make a table:
Update a specific column given a specific row using the UPDATE statement:
Remove a set of values using the DELETE s…