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| author | sueloverso <sue@mongodb.com> | 2017-07-27 21:59:03 -0400 |
|---|---|---|
| committer | Alex Gorrod <alexander.gorrod@mongodb.com> | 2017-07-28 11:59:03 +1000 |
| commit | 83cb4be42c7eeae90633e8fb461a703ed55e8103 (patch) | |
| tree | a4c06120cbcb843eb6c45ff9661f54e5b7a326d8 | |
| parent | f068511994d67711e582d7d1f2959dd7874b39de (diff) | |
| download | mongo-83cb4be42c7eeae90633e8fb461a703ed55e8103.tar.gz | |
WT-3422 Add upgrade/downgrade doc text (#3538)
| -rw-r--r-- | src/docs/upgrade.dox | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/docs/upgrade.dox b/src/docs/upgrade.dox index 7952efa0343..9f8331c9b1f 100644 --- a/src/docs/upgrade.dox +++ b/src/docs/upgrade.dox @@ -60,11 +60,17 @@ the WT_SESSION::upgrade method. Applications wanting the ability to downgrade to previous releases of WiredTiger are constrained in some important ways: -- The underlying data file formats must not have changed between the +- The underlying table file formats must not have changed between the release currently being run and the release to which you are -downgrading. In other words, data file format changes are not backward -compatible, and an upgraded data file cannot be downgraded without being +downgrading. In other words, table file format changes are not backward +compatible, and an upgraded table file cannot be downgraded without being dumped and re-loaded. +- If the underlying log file format changed and you have logging enabled +in the database, in order to retain the ability to downgrade to earlier +releases you must use \c compatibility option in the call to +::wiredtiger_open or WT_CONNECTION::reconfigure. When running at an +earlier compatibility release setting, the log files generated will be +compatible with earlier binaries. <br><br> - Applications concerned with downgrading should configure the ::wiredtiger_open \c config_base value to \c false, so WiredTiger does |