COMPRESS AND COMPACT GEODATABSE IN ARCGIS
Compact Database-
A file geodatabase is stored as a folder of files on disk,
while a personal geodatabase is stored in a single .mdb file. When you first
add data to either of these geodatabases, the records within each file are in
order and are accessed efficiently by the file system. However, as you delete
and add records over time, the records within each file lose their order, and
unused space develops as records are removed and new ones are added elsewhere
in the file. This causes the file system to perform more record-seeking
operations within each file, slowing the rate at which records are accessed.
If we frequently add and delete data, we should compact our
file or personal geodatabase , Compacting tidies up storage by reordering
records and eliminating unused space. After compacting, the data in each file
can be accessed more efficiently. Compacting also reduces the size of each
file—it's possible to be able to reduce the size of a geodatabase by one-half
or more.
For Compacting- Right click on Geodatabase and select
compact Database.
Compress database-
For reduce storage requirements, we can compress vector file
geodatabase feature classes and tables
to a read-only format. Once compressed, display and query performance is
comparable to uncompressed data. we may find it provides slight performance
improvements in some operations but slows slightly in others.
The compression applied is lossless, that is, when we
compress data, no information is lost, regardless of the coordinate system or
types of attribute data the feature class or table contains. Where compressed
datasets differ from uncompressed data is in editing: a compressed dataset is
read-only and therefore cannot be edited or modified in any way except for
changing its name and modifying attribute indexes and metadata.
Once compressed, a dataset looks the same in ArcCatalog and
ArcMap as when it was uncompressed. Also, apart from editing, you work with it
the same way. The compressed data is a direct-access format, so you do not have
to uncompress it each time you access it; ArcGIS and ArcReader read it
directly.
Compression is ideally suited to mature datasets that do not
require further editing. However, if required, a compressed dataset can always
be uncompressed to return it to its original, read/write format.
Entity which can compress-
Geodatabase
Feature dataset
Feature class(Stand Alone)
Table