com.esri.arcgis.geodatabase
Interface ISpatialCacheManager2

All Superinterfaces:

ISpatialCacheManager, Serializable

All Known Subinterfaces:

ISpatialCacheManager3

All Known Implementing Classes:

ISpatialCacheManager2Proxy, ISpatialCacheManager3Proxy, VersionedWorkspace, Workspace

public interface ISpatialCacheManager2
extends ISpatialCacheManager, Serializable

Provides access to members that control the Spatial Cache Management.

Superseded By

ISpatialCacheManager3

Remarks

The ISpatialCacheManager2 interface was added to enable creating a spatial cache by expanding the specified envelope by a specified expansion factor.

Enabling feature caching improves the performance of all spatial searches whose query geometry lies within the cached area and and also improves the performance of all queries that retrieve features by object ID (for example, GetRow, GetFeature, GetRows, and GetFeatures). At ArcGIS release 8.3 and earlier, caching of features using ISpatialCacheManager requires that there be an active edit session. At ArcGIS release 9.0 and higher, using ISpatialCacheManager does not require an active edit session.

Use of the cache is transparent to editing applications. Objects retrieved using non-recycling cursors may be updated and stored by the editing application. As in the uncached case, the geodatabase takes care of ensuring read and query consistency when queries are issued againt updated objects. The cache is exposed to end users as the edit cache in ArcMap for ArcGIS release 8.3 and earlier, and the map cache for ArcGIS releases 9.0 and higher. The cache improves performance significantly for network editing when working with ArcSDE geodatabases.

The SpatialCacheManager optimistically builds caches for features within the workspace. It caches the features in the cache extent for any open feature class. Note that opening a feature class that participates in a topology or geometric network will also open all other feature classes participating in the topology or geometric network. To correctly use the cache, you should be aware of which feature classes are open within a workspace. If a reference to the workspace is returned from a map document, the open feature classes will include all the feature classes for that workspace in the map. If you have opened the workspace through the Geodatabase API, by using a method such as IFeatureWorkspace::OpenFeatureDataset, only those features from feature classes that have been explicitly opened using the IFeatureWorkspace::OpenFeatureClass method will be cached.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Method Summary

void	fillCacheEx(IEnvelope pExtent, double expansionFactor) Fills the spatial cache using the specified extent with an expansion factor.
double	getCacheExpansionFactor() The extent expansion factor for the spatial cache.

Methods inherited from interface com.esri.arcgis.geodatabase.ISpatialCacheManager

emptyCache, fillCache, getCacheExtent, isCacheIsFull

Method Detail

fillCacheEx

void fillCacheEx(IEnvelope pExtent,
                 double expansionFactor)
                 throws IOException,
                        AutomationException

Fills the spatial cache using the specified extent with an expansion factor.

Remarks

FillCacheEx takes an envelope and a parameter used to expand the envelope. The expand factor must be greater than 1 ; 1.1 would expand it by 10%, while 2 would double the size.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

pExtent - A reference to a com.esri.arcgis.geometry.IEnvelope (in)

expansionFactor - The expansionFactor (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getCacheExpansionFactor

double getCacheExpansionFactor()
                               throws IOException,
                                      AutomationException

The extent expansion factor for the spatial cache.

Remarks

The CacheExpansionFilter returns the expansion factor specified after a call to FillCacheEx.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The expansionFactor

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.