feat(tianmu) Add upgrade directory (#510) (#511)

* feat(tianmu) Add upgrade directory (#510) * Optimize the structure of DPN to support memory alignment
stoneatom · Sep 20, 2022 · 08f5ae5 · 08f5ae5
1 parent 208f79d
commit 08f5ae5
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diff --git a/storage/tianmu/core/dpn.h b/storage/tianmu/core/dpn.h
@@ -42,7 +42,8 @@ struct DPN final {
   uint8_t delete_compressed : 1;
   uint8_t data_compressed : 1;
   uint8_t no_compress : 1;
-  uint8_t padding[1];  // Memory aligned padding has no practical effect
+  uint8_t paddingBit : 1; // Memory aligned padding has no practical effect
+  uint8_t padding[7];     // Memory aligned padding has no practical effect
 
   uint32_t base;           // index of the DPN from which we copied, used by local pack
   uint32_t numOfRecords;   // number of records

diff --git a/storage/tianmu/upgrade/README.md b/storage/tianmu/upgrade/README.md
@@ -0,0 +1,7 @@
+The Tianmu engine needs an upgrade tools, which provides some tools for 
+upgrade Tianmu from an old version to a new version. 
+The new version maybe changes the format of meta-data or format of data. 
+These format change will lead the new version of StoneDB can read the old-format data. 
+Therefore, StoneDB should provide an upgrading solution.
+
+All our information about Tianmu upgrading is in this directory.