Iteration 2: Addresses Tobys comments

src/main/java/net/snowflake/ingest/streaming/SnowflakeStreamingIngestChannel.java

@@ -256,7 +256,9 @@ InsertValidationResponse insertRows(
   String getLatestCommittedOffsetToken();
 
   /**
-   * Gets the table schema associated with this channel
+   * Gets the table schema associated with this channel. Note that this is the table schema at the
+   * time of a channel open event. The schema may be changed on the Snowflake side in which case
+   * this will continue to show an old schema version until the channel is re-opened.
    *
    * @return map representing Column Name -> Column Properties
    */

src/main/java/net/snowflake/ingest/streaming/internal/ColumnProperties.java

@@ -2,7 +2,8 @@
 
 /**
  * Class that encapsulates column properties. These are the same properties showed in the output of
- * <a href="https://docs.snowflake.com/en/sql-reference/sql/show-columns">SHOW COLUMNS</a>
+ * <a href="https://docs.snowflake.com/en/sql-reference/sql/show-columns">SHOW COLUMNS</a>. Note
+ * that this is slightly different than the internal column metadata used elsewhere in this SDK.
  */
 public class ColumnProperties {
   private String type;

src/main/java/net/snowflake/ingest/streaming/internal/SnowflakeStreamingIngestChannelInternal.java

@@ -126,11 +126,11 @@ class SnowflakeStreamingIngestChannelInternal<T> implements SnowflakeStreamingIn
             this::collectRowSize,
             channelState,
             new ClientBufferParameters(owningClient));
+    this.tableColumns = new HashMap<>();
     logger.logInfo(
         "Channel={} created for table={}",
         this.channelFlushContext.getName(),
         this.channelFlushContext.getTableName());
-    this.tableColumns = new HashMap<>();
   }
 
   /**