Summary: This writes up expounds the methodical procedures to reorganize and rebuild any fragmented index in SQL Server. The entire techniques are estranged into various subdivisions to make this operation uncomplicated for users. Through stated procedures, users possibly will accomplish the task without any data loss. Towards the last part of this article, it also carries a professional method of rebuilding index in SQL Server.
The SQL Server index is analogous to the index of any book. This index assists to get a quick idea about contained data, but instead of navigating any book, it is a catalog of the SQL Server database.
Whenever any search operation becomes performed in SQL, the SQL Server searches the value in its index and after that locates that entire row of data. Therefore, SQL does not perform a full table scanning process for searching any data and present us the required data through its indexes.
The SQL Server automatically sustains its indexes after executing any operation in it as INSERT, UPDATE, MERGE and DELETE. When the logical order of pages in an index does not match with its physical data order, the index fragmentation happens. The deeply fragmented index mortifies the performance of SQL Server and it may the cause of slow responding OS.
The fragmentation also impinges on the executed queries and range scanning process. A lot of unused space may increase the number of pages in index.
The index fragmentation can be monitored only via rebuilding or re-creating that index. This process eliminates the fragmentation and repossesses the storage space by compacting the size of pages.
In this defragmentation process, we set the particular or existing fill factor, and then, it maintains the index rows in adjacent pages. Rebuilding any index utilizes only some negligible system resources. reorganizing defragments the leaf level of the clustered index and non-clustered indexes on tables. Rebuilding indexes also compact the number of index pages. The index compaction is based on the presented fill factor’s value.
The information regarding internal index fragmentation, can be easily detected by the dynamic management view (DMV) that is sys.dm_db_index_physical_stats. The DMV defragments the index information and returns it to its exact size. Via DMV, users can acquire the information regarding to the amount of fragmentation in rows on a specific data page. This can detect that the data reorganization is essential or not.
avg_fragmentation_in_percent: average percent of logical fragmentation is inaccurate in the index
fragment_count: number of fragments in the index
avg_fragment_size_in_pages: average number of pages in a single fragment in one index
Once the fragmentation in the index has been perceived then, its establishment is the next step. There is a usually a conventional resolution for each level of fragmentation based on the proportion of fragmentation:
If fragmentation < 10% – no need of defragmentation. It is an acceptable amount and does not influence the working of SQL Server
If fragmentation ≤ 10-30% –Index restructuring is required
If fragmentation ≥ 30% – Index rebuilding is must
Reconstruction of an index is necessary when the index fragmentation has attains to a significant percentage. In this section, we will rebuild index via SQL Server Management Studio and Transact-SQL.
To rebuild any fragmented index of SQL Server, there may be two possible conditions i.e. rebuilding a single index another rebuilding all indexes of a table. Here are the total solutions of how to reorganize and rebuild any index via SQL Server Management Studio:
Case 1: Reorganizing a single Index
In this section, we will discuss the method of recognizing and rebuilding any single or multiple indexes of any table using Transact-SQL.
Case 1: Reorganizing a Single Defragmented Index
Case 2: Reorganizing All defragmented Indexes
Rebuilding all defragmented Indexes
Manual methods are risky as well as time taking too. Users must need the technical knowledge for rebuilding indexes in SQL Server. Therefore, for preventing users via these cons of manual methods, we represent a powerful solution: SQL Recovery software. It automatically manages the index defragmentation along with its statistics updates intended for single or additional databases. This is the method of automatically rebuilding or reorganizing any index as per its fragmentation level. This is capable to recover the data that is affected by wallet ransomware attack.
After understanding the significance of fragmentation in indexes of SQL Server, it becomes essential to recognize and rebuild the indexes. For rebuilding the fragmented indexes, we have discussed various methods of rebuilding index in SQL Server. Users can accomplish this task in two different manual and automatic manners as mentioned above. The SQL Recovery tool is one of the best solutions to execute the mentioned task in a hassle-free manner. Now, users can opt any of the suitable technique in order to do this.