fix: fix altering schema too much corrupting meta file

src/tsdb/src/tsdbMeta.c

@@ -1250,8 +1250,14 @@ static int tsdbEncodeTable(void **buf, STable *pTable) {
     tlen += taosEncodeFixedU64(buf, TABLE_SUID(pTable));
     tlen += tdEncodeKVRow(buf, pTable->tagVal);
   } else {
-    tlen += taosEncodeFixedU8(buf, (uint8_t)taosArrayGetSize(pTable->schema));
-    for (int i = 0; i < taosArrayGetSize(pTable->schema); i++) {
+    uint32_t arraySize = (uint32_t)taosArrayGetSize(pTable->schema); 
+    if(arraySize > UINT8_MAX) {
+      tlen += taosEncodeFixedU8(buf, 0);
+      tlen += taosEncodeFixedU32(buf, arraySize);
+    } else {
+      tlen += taosEncodeFixedU8(buf, (uint8_t)arraySize);
+    }
+    for (uint32_t i = 0; i < arraySize; i++) {
       STSchema *pSchema = taosArrayGetP(pTable->schema, i);
       tlen += tdEncodeSchema(buf, pSchema);
     }
@@ -1284,8 +1290,11 @@ static void *tsdbDecodeTable(void *buf, STable **pRTable) {
     buf = taosDecodeFixedU64(buf, &TABLE_SUID(pTable));
     buf = tdDecodeKVRow(buf, &(pTable->tagVal));
   } else {
-    uint8_t nSchemas;
-    buf = taosDecodeFixedU8(buf, &nSchemas);
+    uint32_t nSchemas;
+    buf = taosDecodeFixedU8(buf, (uint8_t *)&nSchemas);
+    if(nSchemas == 0) {
+      buf = taosDecodeFixedU32(buf, &nSchemas);
+    }
     for (int i = 0; i < nSchemas; i++) {
       STSchema *pSchema;
       buf = tdDecodeSchema(buf, &pSchema);
@@ -1485,4 +1494,4 @@ static void tsdbFreeTableSchema(STable *pTable) {
 
     taosArrayDestroy(pTable->schema);
   }
-}
\ No newline at end of file
+}