Synchronize Mosaic Dataset (Data Management)
Summary
Rebuilds or updates each raster item in the mosaic dataset and updates affected fields in the attribute table, using the raster type and options that were used when it was originally added.
Synchronization is a one-way operation: changes in the source data can be synchronized to the mosaic dataset’s attribute table, but changes in the attribute table will not affect the source data (but may be overwritten by the synchronization).
Changes made with the synchronization cannot be undone. You may want to create a backup copy if you've made modifications to your mosaic data that could be overwritten.
Usage
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You can use a selection set with this tool to limit the raster items that are updated. When there is a selection or query, only those items will be processed.
The synchronization can add new items, update existing items, or remove items.
Stale items refer to source rasters that have been changed since the mosaic dataset has been created or the last time the mosaic dataset has been synchronized. For instance, the georeferencing may have been updated or the pyramids may have been built.
Since the raster items are reconstructed, any modifications made to these items since the last time they were built would be lost, such as editing functions or content in the attribute table.
If you choose to remove items that have broken data sources, make sure that all your network connections are working properly—this tool will remove any items that cannot be accessed.
This tool can also build pyramids and calculate statistics on the source rasters, and create thumbnails and raster cache for the raster items.
This tool is particularly useful for keeping mosaic datasets up-to-date. If new raster datasets have been added to the workspaces that this mosaic dataset accesses, the new raster datasets can be added into the mosaic dataset. Mosaic datasets that are populated using tables that reside in an externally managed database can also be updated with this tool.
Once the synchronization has completed, the operations listed in Mosaic Dataset Options will take place.
This tool can be used to generate the cache for an item in the mosaic dataset. Items that can always be cached are created from the following data: LAS files, LAS dataset, and terrains. Items can also be cached using the Cached Raster function.
Database fragmentation and frequent data manipulation may increase the size of your mosaic dataset dramatically. If your database size is inflated due to constant transactions, you should run the Compact tool.
Syntax
Parameter | Explanation | Data Type |
in_mosaic_dataset |
The path and name of the mosaic dataset. | Image Service; Mosaic Layer; String |
where_clause (Optional) |
You can use SQL to define which mosaic dataset items will be synchronized. If no query is specified, then all the mosaic dataset items will be synchronized. | SQL Expression |
new_items (Optional) | Choose whether to synchronize your mosaic dataset with newly added items. If you choose to use this option, the item's workspace will be searched for new data. When data is added to the mosaic dataset, it will use the same raster type as the other items within the same workspace. If you choose to update with the new items, you can optionally choose whether to update cell size ranges, boundary, overviews, and whether to also update existing items.
| Boolean |
sync_only_stale (Optional) |
Choose whether to update all primary items or only stale primary items. An item is considered stale if the corresponding source files that are used to construct the raster values are modified after the item is created. For instance, the georeferencing may have been updated or the pyramids may have been built.
| Boolean |
update_cellsize_ranges (Optional) | Choose whether to update the cell size ranges.
| Boolean |
update_boundary (Optional) | Choose whether to update the boundary.
| Boolean |
update_overviews (Optional) | Choose whether to update any obsolete overviews. The overview becomes obsolete if any underlying rasters have been modified.
| Boolean |
build_pyramids (Optional) |
Choose whether to build pyramids for the specified mosaic dataset items. Pyramids can be built for each raster item in the mosaic dataset. Pyramids can improve the speed at which each raster is displayed.
Pyramids will not be built for newly added items, if the items are added in the same instance of running this tool. | Boolean |
calculate_statistics (Optional) |
Choose whether to calculate statistics for the source raster of the specified mosaic dataset items. Statistics are required for your mosaic dataset when performing certain tasks, such as applying a contrast stretch.
Statistics will not be built for newly added items, if the items are added in the same instance of running this tool. | Boolean |
build_thumbnails (Optional) |
Choose whether to build thumbnails for the specified mosaic dataset items. Thumbnails are small, highly resampled images that can be created for each raster item in the mosaic definition. Thumbnails can be accessed when the mosaic dataset is accessed as an image service and will display as part of the metadata (Item Description).
Thumbnails will not be built for newly added items, if the items are added in the same instance of running this tool. | Boolean |
build_item_cache (Optional) | Choose whether to build a cache for the specified mosaic dataset items. A cache can be created when you've added data using the LAS, Terrain, or LAS Dataset raster types. Items can also be cached using the Cached Raster function.
The cache will not be built for newly added items, if the items are added in the same instance of running this tool. | Boolean |
rebuild_raster (Optional) | Choose whether to rebuild the raster items from the data source using the original raster type.
This will only affect items that will be synchronized. This parameter is not applicable if UPDATE_WITH_NEW_ITEMS has been chosen. | Boolean |
update_fields (Optional) | Choose whether to update the fields within the table. This will only affect items that will be synchronized.
If you choose to update the fields, you can control which fields are updates by selecting them in the fields_to_update parameter. If you have made edits to some of the fields, you may want to remove them in the fields_to_update parameter. | Boolean |
fields_to_update [field_to_update,...] (Optional) | Specify which fields should be updated. This parameter is only valid if the option for the update_fields parameter is UPDATE_FIELDS. If you have made edits to some of the fields, you may want to make sure they are not listed. The RASTER column can be refreshed, even if the REBUILD_RASTER keyword is not used. However, if the REBUILD_RASTER is being used, the RASTER column is rebuilt, even if this field is not specified. | String |
existing_items (Optional) | Choose whether you would like to update existing items within your mosaic dataset. If you choose this option, you can then choose which existing parameters you would like to update: sync_only_stale, build_pyramids, calculate_statistics, build_thumbnails, build_item_cache, update_fields, or fields_to_update.
| Boolean |
broken_items (Optional) | Choose whether you want to remove any broken links. Make sure that all your network connections are working properly—this tool will remove any items that cannot be accessed.
| Boolean |
skip_existing_items (Optional) | If the UPDATE_WITH_NEW_ITEMS keyword is used, then you can also choose whether to skip or to update existing mosaic dataset items with the modified files from disk.
| Boolean |
Code Sample
This is a Python sample for SynchronizeMosaicDataset.
import arcpy
arcpy.SynchronizeMosaicDataset_management(
"c:/data/syncmd.gdb/md", "Year>1999", "NO_NEW_ITEMS", "SYNC_STALE",
"#", "#", "#", "NO_PYRAMIDS", "NO_STATISTICS", "NO_THUMBNAILS",
"NO_ITEM_CACHE", "NO_RASTER", "NO_FIELDS", "#", "#")
This is a Python script sample for SynchronizeMosaicDataset.
# Synchronize source and add new data
import arcpy
arcpy.env.workspace = "C:/Workspace"
mdname = "syncmd.gdb/mdnew"
query = "#"
updatenew = "UPDATE_WITH_NEW_ITEMS"
syncstale = "SYNC_STALE"
updatecs = "#"
updatebnd = "#"
updateovr = "#"
buildpy = "NO_PYRAMIDS"
calcstats = "NO_STATISTICS"
buildthumb = "NO_THUMBNAILS"
buildcache = "NO_ITEM_CACHE"
updateras = "NO_RASTER"
updatefield = "NO_FIELDS"
fields = "#"
arcpy.SynchronizeMosaicDataset_management(
mdname, query, updatenew, syncstale, updatecs, updatebnd,
updateovr, buildpy, calcstats, buildthumb, buildcache,
updateras, updatefield, fields)