Doc: vrt.rst: add explanations for block size

Aarchbishop · Dec 21, 2022 · b8df3fd · b8df3fd
1 parent e641b13
commit b8df3fd
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/doc/source/drivers/raster/vrt.rst b/doc/source/drivers/raster/vrt.rst
@@ -59,6 +59,16 @@ The following creations options are supported:
 
 -  **BLOCKYSIZE=n**: (GDAL >= 3.7) Sets block height.
 
+Setting explicitly the block size is an advanced setting that should only be
+used, when the user has determined that it is needed. By default the block size
+is set to:
+
+- 128x128 for a source-based VRT raster band. Unless the VRT is made of a single
+  source and this single source is not subsetted, in which case the block size of
+  the unique source will be set as the VRT raster band block size)
+
+- 512x128 for a warped VRT.
+
 .vrt Format
 -----------