What is the Difference Between Rebuild and Reorganize indexes ?

Rebuilding Index:-

• Rebuilding task dropping existing one and create new one.
• Locking’s and blockings will occurred, during the rebuilding process.
• Generally rebuild process runs faster than Reorganizing index.
• More Disk space is required for rebuilding operation.
• Index and columns stats are automatically updated, as a part of rebuilding process.
• When the fragmentation is more than 30% better rebuild index.
• We can rebuild online or offline
• Example:-

ALTER INDEX (indexname) ON (tablename)

REBUILD;

Reorganizing Index:-

• Reorganizing task is just modifying the existing index.
• User can access database during the reorganizing process.
• Generally reorganizing index takes long time rather than rebuilding task.
• Less space is required.
• Index and statics need to be updated after reorganizing index
• If the fragmentation is B/W 5% to 30% better to Reorganizing Index.
• Reorganizing index process is offline only.
• Example

ALTER INDEX (indexname) ON (tablename) REORGANIZE;