Are there any cases where indexes are not a good idea?

In what situation would you not use an index?

When Should We Avoid Using Indexes?1Indexes should not be used on tables containing few records.2Tables that have frequent, large batch updates or insert operations.3Indexes should not be used on columns that contain a high number of NULL values.4Indexes should not be used on the columns that are frequently manipulated.

What are the negative effects of indexes?

If you index every column in every table, then data modifications would slow down.Too many indexes also add compilation overhead and can increase the likelihood of deadlocks due to different data access paths. ... @TT. . . .

Why many indexes are not good for performance?

The reason that having to many indexes is a bad thing is that it dramatically increases the amount of writing that needs to be done to the table. This happens in a couple of different places. When a write happens the data first is logged to the transaction log.

What is the downside of a database index?

The downside to adding indexes to a table is that they affect the performance of writes. Moreover, improperly created indexes can even adversely affect SELECT queries! Any table configuration where performance suffers due to excessive, improper, or missing indexes is considered to be poor indexing.