How do you improve database performance for table having a large number a row?

When you have to join a large table and there are conditions on said table, you can increase database performance by transferring your data in a temp table, and then making a join on that. Your temp table will have fewer rows than the original (large) table, so the join will finish faster!

How do I update a large table with millions of rows in MySQL?

A few things to try:

1. Don’t update rows unless they need it. Skip the rows that already have the correct value.
2. Do the update in chunks of a few thousand rows, and repeat the update operation until the whole table is updated. I guess tableA contains an id column.
3. Don’t do the update at all.

What is the best way to analyze database indexes so that they run in an optimal fashion?

General Guidelines for Index Design

1. Use large number of indexes on tables to improve the query performance.
2. Use clustered and non-clustered indexes and understand the purpose of each index.
3. Avoid frequently updated indexes on a table to improve performance.
4. Use a non-clustered index to reduce the query execution time.

How do you update a large table with millions of rows in Oracle?

Efficient way to UPDATE bulk of records in Oracle Database

1. Update each record individually and COMMIT in FOR LOOP.
2. Update each record individually in FOR LOOP but COMMIT after the loop.
3. BULK UPDATE using BULK COLLECT and FOR ALL.
4. DIRECT UPDATE SQL.
5. MERGE STATEMENT.
6. UPDATE using INLINE View Method.

How do you update data?

First, specify the table name that you want to change data in the UPDATE clause. Second, assign a new value for the column that you want to update. In case you want to update data in multiple columns, each column = value pair is separated by a comma (,). Third, specify which rows you want to update in the WHERE clause.