Fragmentation

The Fragmentation panel allows for reviewing index fragmentation and performing defragmentation.

Index fragmentation means that the data within an index is fragmented or scattered across physical memory, meaning that the logical order of leaves in the index does not match the physical order of data on the disk. This can occur due to regular insertion, deletion, and update operations in the database, which can eventually lead to degraded query performance as it requires a significant number of jumps between different parts of the disk to access the data.

The functionality is accessed on Performance | Edit Indices panel in Administration panel.

The following is a description of the functionality of the form.

1. Fragmentation parameters

(Plus)	By clicking, the following options are available: Collapse All - collapse whole fragmentation table. Expand All - expand whole fragmentation table. Collapse Selected - collapse only selected indices in fragmentation table. Expand Selected - expand only selected indices in fragmentation table. Collapse All for Selection - collapse all selected indices. Expand All for Selection -  expand all selected indices. Select All - select all indices in fragmentation table. Undo Merge - restore to the original state before merging.
Fragmentation Percentage	Specify the percentage (number)  of fragmentation.  Percentage fragmentation refers to the degree of data scattering or disorganization within a database or on a disk. Fragmentation occurs when data is physically arranged in a manner that does not match its logical sequence or structure. The percentage fragmentation measures how much data is distributed or scattered compared to its logical organization.   HINT High percentage fragmentation can negatively impact system performance by requiring more physical operations to access data. Therefore, it is important to periodically perform procedures such as defragmentation, which reorganizes data into a more logical sequence, thereby improving system performance efficiency.
Search	By clicking, all indexes that have a fragmentation value equal to or greater than the entered value, will be collected.

2. Fragmentation table

Database	Database where are tabel with indices for fragmentation.
Table	Table where are indices for fragmentation.
Sel.	By clicking, index is selected ().
Index	Name of index.
Fragmentation	Number of index fragmentation.
AVG	Average number of indices fragmentation.

3. Defragmentation

Index defragmentation is a process of optimizing the database where the goal is to reduce index fragmentation.

This is typically achieved by reorganizing or rebuilding the index to align the sequence of data on disk with the logical order of leaves in the index. Index defragmentation can improve query performance and shorten system response time.