diff --git a/Documentation/Books/Manual/Upgrading/VersionSpecific/Upgrading34.md b/Documentation/Books/Manual/Upgrading/VersionSpecific/Upgrading34.md index 649e175e65..bfbee60ef9 100644 --- a/Documentation/Books/Manual/Upgrading/VersionSpecific/Upgrading34.md +++ b/Documentation/Books/Manual/Upgrading/VersionSpecific/Upgrading34.md @@ -1,6 +1,32 @@ Upgrading to ArangoDB 3.4 ========================= -Please be sure that you have checked the list of [incompatible changes in 3.4](../../ReleaseNotes/UpgradingChanges34.md) +Please be sure that you have checked the list of +[incompatible changes in 3.4](../../ReleaseNotes/UpgradingChanges34.md) before upgrading. +Upon upgrading from 3.3 to 3.4, the following storage engine-specific data conversion tasks +will be executed: + +- **MMFiles storage engine:** + + All collection datafiles will be rewritten into a + new data format. This data format is required in order to support using the collections + in [ArangoSearch Views](../../Views/ArangoSearch/README.md) introduced in ArangoDB 3.4. + + The conversion will read each datafile sequentially and write out a new datafile in the + new format sequentially. This means the disk will be involved, but both reading and + writing are done in a sequential fashion. Preliminary tests have shown that it will need + at most 2-3 times as long as it takes to copy the database directory. + +- **RocksDB storage engine:** + + All existing geo indexes will be rewritten into a new + data format. This data format is required for using the indexes with the improved + [geo index feature](../../Indexing/Geo.md) in ArangoDB 3.4. + + Preliminary tests have shown that the conversion can process about 500K to 1M geo index + entries per second on commodity hardware. + +If you upgrade without any existing data (new blank data folder), then none of these tasks +needs to be run because the datafiles will be created using the new format already.