How can we get the list of all the indexes on a table?

How can we get the list of all the indexes on a table?

To list all indexes of a specific table:

1. SHOW INDEX FROM table_name FROM db_name;
2. SHOW INDEX FROM db_name. table_name;
3. SELECT DISTINCT TABLE_NAME, INDEX_NAME FROM INFORMATION_SCHEMA. STATISTICS WHERE TABLE_SCHEMA = `schema_name`;
4. SELECT DISTINCT TABLE_NAME, INDEX_NAME FROM INFORMATION_SCHEMA. STATISTICS;

Which is faster clustered or nonclustered index?

If you want to select only the index value that is used to create and index, non-clustered indexes are faster. On the other hand, with clustered indexes since all the records are already sorted, the SELECT operation is faster if the data is being selected from columns other than the column with clustered index.

How do I find the index of a table in SQL?

On Oracle:

1. Determine all indexes on table: SELECT index_name FROM user_indexes WHERE table_name = :table.
2. Determine columns indexes and columns on index: SELECT index_name , column_position , column_name FROM user_ind_columns WHERE table_name = :table ORDER BY index_name, column_order.

When to create indexes on columns in SQL?

It is recommended to create the indexes on columns that are used in the query predicates and join conditions in the correct order that is specified in the predicate. In this way, the goal is keeping the index key short, without including the rarely used columns, in order to minimize the index complexity, storage and maintenance overheads.

How does creating indexes on a table affect performance?

Creating a large number of indexes on a database table affects data modification (e.g. Updates) operations performance. When you add or modify a row in the underlying table, the row will also be adjusted appropriately in all related table indexes.

Is it recommended to create an index on a small table?

It is not recommended to create indexes on small tables, as it takes the SQL Server Engine less time scanning the underlying table than traversing the index when searching for a specific data.

How is the weight of a query related to the index?

You can also see that the weight of the query that is scanning the index is 92% of the overall weight, compared to the one that is scanning the index with weight equal to 8% of the overall weight, as shown clearly below: