(iotdb) branch master updated: Optimize TsTable with Copy-on-Write pattern for thread-safe concurrent access (#17069)

[jiangtian]

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The following commit(s) were added to refs/heads/master by this push:
     new 8455b8c4c1f Optimize TsTable with Copy-on-Write pattern for 
thread-safe concurrent access (#17069)
8455b8c4c1f is described below

commit 8455b8c4c1fa8c8da8cccf925213057b6d277c85
Author: Zhenyu Luo <zhe...@apache.org>
AuthorDate: Sat Jan 31 07:45:47 2026 +0800

    Optimize TsTable with Copy-on-Write pattern for thread-safe concurrent 
access (#17069)
    
    * Optimize TsTable with Copy-on-Write pattern for thread-safe concurrent 
access
    
    - Change columnSchemaMap, tagColumnIndexMap, and idColumnIndexMap from 
final to volatile
    - Implement Copy-on-Write in executeWrite method:
      1. Create local copies of maps before modification
      2. Execute write operations on local copies
      3. Atomically update class fields after write completes
    - Add WriteOperation functional interface to pass map copies to write 
operations
    - Add executeWriteWithTransform for efficient single-pass transformation 
during copy
    - Optimize renameColumnSchema to preserve column order with single-pass copy
    - This ensures readers see either complete old data or complete new data, 
avoiding ConcurrentModificationException
    
    * fix
    
    * fix
    
    * fix
    
    * Revert "fix"
    
    This reverts commit 2155558217aabe2a0dd7dc09e85c569597d38b9f.
    
    * Revert "fix"
    
    This reverts commit 7e798b1ba71365cc7ad8a76c5e83122ead6a3744.
    
    * Revert "fix"
    
    This reverts commit 9b221b192be5ecf73fb4bd23ec2a7d3009888bfd.
    
    * Revert "Optimize TsTable with Copy-on-Write pattern for thread-safe 
concurrent access"
    
    This reverts commit 3eeaf83f3dc3c32ee944daf3f7ff9b456e88b29e.
    
    * fix
---
 .../apache/iotdb/db/schemaengine/table/DataNodeTableCache.java    | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git 
a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/table/DataNodeTableCache.java
 
b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/table/DataNodeTableCache.java
index 9beab9bcfff..64fa5f34ac4 100644
--- 
a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/table/DataNodeTableCache.java
+++ 
b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/table/DataNodeTableCache.java
@@ -288,13 +288,17 @@ public class DataNodeTableCache implements ITableCache {
     try {
       if (databaseTableMap.containsKey(database)
           && databaseTableMap.get(database).containsKey(tableName)) {
-        
databaseTableMap.get(database).get(tableName).removeColumnSchema(columnName);
+        final TsTable copyTable = new 
TsTable(databaseTableMap.get(database).get(tableName));
+        copyTable.removeColumnSchema(columnName);
+        databaseTableMap.get(database).put(tableName, copyTable);
       }
       if (preUpdateTableMap.containsKey(database)
           && preUpdateTableMap.get(database).containsKey(tableName)) {
         final Pair<TsTable, Long> tableVersionPair = 
preUpdateTableMap.get(database).get(tableName);
         if (Objects.nonNull(tableVersionPair.getLeft())) {
-          tableVersionPair.getLeft().removeColumnSchema(columnName);
+          final TsTable copyTable = new TsTable(tableVersionPair.getLeft());
+          copyTable.removeColumnSchema(columnName);
+          tableVersionPair.setLeft(copyTable);
         }
         tableVersionPair.setRight(tableVersionPair.getRight() + 1);
       }