A method of grouping multiple layers and treating them as one big layer.
- Partitioned layers can be used only on ArcSDE vector layers and not with shapefiles, images, or ArcSDE raster layers.
- Partitions are valid only when used in an Image Service.
- Partitioned layers cannot be geocoded.
- Partitioned layers cannot have related tables.
- Partitioned layers do not support stored queries.
- PARTITION is a method of grouping multiple layers and treating them as one layer. Each piece of the partitioned layer is a tile segment that must include an ENVELOPE. The partitioned layers can be a traditional tile where no envelopes overlap, or the partitioned layers can also have overlapping envelopes. For example, if data from two states is used as partitioned layers, the envelopes will likely overlap. In the case of California and Nevada, the extents of both states overlap each other as shown in the figure below. During a query, if a point lies within both extents, both partitioned layers are queried.
A single layer can also be partitioned multiple times. In the next example showing California and Nevada, the states are divided into a series of smaller partitions. Within each state, no partitions overlap, although they could. There is still some overlap between the Nevada and California partitions, but the overlap area between the two states is much smaller. The advantage of using smaller partitions is that smaller areas are searched during a query and the overlapping extents are smaller.
Each PARTITION envelope is an index to the layer. If data in a layer is not included in one of the PARTITION envelopes, depending on the requested extent, the data may or may not be retrieved. If the requested extent is completely outside any of the PARTITION envelopes, no data is returned. If the requested extent includes part of a PARTITION envelope, then the data is returned.
- All layers described within a PARTITION must be present in the ArcSDE database. If one reference is incorrect, the entire layer will not display.
- DATASET name can be an arbitrary name. The actual ArcSDE layer names must be specified in PARTITION name.
Attribute Descriptions for PARTITION
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|name||Layer name for partition. Specifies ArcSDE layer. Multiple ArcSDE layers with the same name are permitted. Performance is generally better if the field name is all upper case. In the PARTITION example, CALIFORNIA.STREET02 is used twice. The ENVELOPE is different for each PARTITION.|
Examples for PARTITION
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|<?xml version="1.0" encoding="UTF-8"?>|
<LOCALE country="US" language="en" variant="" />
<UIFONT color="0,0,0" name="Arial" size="12" style="regular" />
<ENVELOPE minx="-124.0" miny="32.0" maxx="-114.0" maxy="42.0"/>
<MAPUNITS units="decimal_degrees" />
<FILTERCOORDSYS id="4326" />
<SDEWORKSPACE name="sde-1" server="CALIFORNIA" instance="port:5150" user="street_data" password="AFXOR"/>
<LAYER type="featureclass" name="Streets" visible="true" id="1">
<DATASET name="CALIFORNIA.STREET" type="line" workspace="sde-1">
<ENVELOPE minx="-124.0" miny="36.0" maxx="-116.0" maxy="42.0"/>
<ENVELOPE minx="-122.0" miny="33.0" maxx="-114.0" maxy="36.0"/>
<ENVELOPE minx="-117.0" miny="32.0" maxx="-113.0" maxy="33.0"/>
<SIMPLELINESYMBOL type="solid" width="3" color="102,102,102" />