MyCATApache/Mycat-Server · error · SQLNonTransientException

can't suport district table + tableName + schema: +…

Error message

can't suport district table  + tableName +  schema: + schema.getName() +  for global table

What it means

When routing a district (dist) table, RouterUtil checks tableConfig.isGlobalTable() and refuses the operation: global tables are replicated to all nodes and have no district partitioning, so a district-table route is meaningless. It throws SQLNonTransientException naming the table and schema.

Solutions

  1. Remove type="global" from the table in schema.xml if it should be district/sharded, then reload
  2. Keep the table global and route via normal global-table logic instead of routeToDistTable
  3. Update application SQL/ORM so global tables are not passed through the dist-table routing path

Example fix

// before (schema.xml)
<table name="dict" type="global" dataNode="dn1,dn2"/>
// routed as district table
// after
<table name="dict" dataNode="dn1,dn2" rule="mod-rule"/> // non-global, or use normal route
Defensive patterns

Strategy: validation

Validate before calling

// verify the table is not global before district routing
// (via MyCat management port)
// mysql -uuser -p -P9066 -> show @@schema; / inspect schema.xml
boolean isGlobal = schemaXmlTableEntry(tableName).attr("type").equals("global");
if (isGlobal) throw new IllegalStateException("Use normal routing for global table " + tableName);

Try / catch

try {
    execute(sql);
} catch (SQLNonTransientException e) {
    if (e.getMessage().contains("can't suport district table"))
        throw new IllegalStateException("Global table cannot use district routing: " + e.getMessage(), e);
    throw e;
}

Prevention

When it happens

Trigger: Invoking the district-table routing method (routeToDistTable) on a table declared with type="global" in schema.xml — e.g. a JOIN or query path that treats the global table as a dist table.

Common situations: Table recently changed from global to sharded (or vice versa) in schema.xml; JOIN routing logic misidentifies a global table as a district table; developer copied a dist-table route call for a replicated lookup table.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/3dc1770e1ef70d28. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/route/util/RouterUtil.java:1441

        LayerCachePool cachePool, boolean isSelect, Map.Entry<String, Map<String, Set<ColumnRoutePair>>> entry) throws SQLNonTransientException {


        String tableName = null;
        if (entry != null) {
            tableName = entry.getKey().toUpperCase();
        } else {
            List<String> tables = rrs.getTables();
            tableName = tables.get(0);
        }
        TableConfig tableConfig = schema.getTables().get(tableName);
        if(tableConfig == null) {
            String msg = "can't find table define in schema " + tableName + " schema:" + schema.getName();
            LOGGER.warn(msg);
            throw new SQLNonTransientException(msg);
        }
        if(tableConfig.isGlobalTable()){
            String msg = "can't suport district table  " + tableName + " schema:" + schema.getName() + " for global table ";
            LOGGER.warn(msg);
            throw new SQLNonTransientException(msg);
        }
        String partionCol = tableConfig.getPartitionColumn();
    //  String primaryKey = tableConfig.getPrimaryKey();
        //boolean isLoadData=false;
    
        Set<String> tablesRouteSet = new HashSet<String>();
    
        List<String> dataNodes = tableConfig.getDataNodes();
        if(dataNodes.size()>1){
            String msg = "can't suport district table  " + tableName + " schema:" + schema.getName() + " for mutiple dataNode " + dataNodes;
            LOGGER.warn(msg);
            throw new SQLNonTransientException(msg);
        }
        String dataNode = dataNodes.get(0);
    
        RouteResultsetNode[] nodes = null;
        //主键查找缓存暂时不实现

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