What is Reindexing in SQL?

What is Reindexing in SQL?

Reindexing tables is an important part of good database housekeeping, because it reorganizes the indexes and restores speedy access. Microsoft’s SQL Server has a handy command that rebuilds all indexes in a table. Oracle users typically rebuild each index in a table individually.

What does Reindexing a database mean?

REINDEX rebuilds an index using the data stored in the index’s table, replacing the old copy of the index. There are several scenarios in which to use REINDEX: An index has become corrupted, and no longer contains valid data. Such indexes are useless but it can be convenient to use REINDEX to rebuild them.

How do I cache SQL results?

To set up the results cache database you need to do the following:

1. Step 1: Install and Configure the Database Server.
2. Step 2: Run the SQL Script to Create the Cache Database.
3. Step 3: Create the JDBC Data Source for the Cache Database.

Why does SQL Server rebuild every single index?

They rebuild (or defrag) every single index in the database, every time, whether it’s necessary or not. The maintenance plans ignore whether the table’s even had a single write since the last time it was maintained. This is a problem because rebuilding and defragmenting indexes causes SQL Server to write to the transaction log.

Why does SQL Server index take so long?

  This means every time we need to scan the index, it’ll take 10% longer (1,100 pages instead of 1,000).   This also means we need more memory to cache the same amount of data – because SQL Server has to cache the empty space on each page.   Our lowest unit of caching is a single page, not a record.

How does TRUNCATE TABLE affect table structure and indexes?

“TRUNCATE TABLE removes all rows from a table, but the table structure and its columns, constraints, indexes and so on remain. The counter used by an identity for new rows is reset to the seed for the column. If you want to retain the identity counter, use DELETE instead.

What should I do if my SQL Server index is fragmentation?

If you can’t cache the database in memory, or you want to fix it on disk anyway, you can solve it by rebuilding or defragmenting the index. Most folks do this with maintenance plans, but those have a nasty problem. They rebuild (or defrag) every single index in the database, every time, whether it’s necessary or not.