Update docs

Author: anlowee

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpFilterToKqlConverter.java

@@ -143,7 +143,7 @@ private ClpExpression handleBetween(CallExpression node)
     {
         if (node.getArguments().size() != 3) {
             throw new PrestoException(CLP_PUSHDOWN_UNSUPPORTED_EXPRESSION,
-                    "Between operator must have exactly three arguments. Received: " + node);
+                    "BETWEEN operator must have exactly three arguments. Received: " + node);
         }
         if (!(node.getArguments().get(0) instanceof VariableReferenceExpression)
                 || !(node.getArguments().get(1) instanceof ConstantExpression)

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpMetadataFilterProvider.java

@@ -57,9 +57,9 @@
  *   <li>{@code rangeMapping} (optional): specifies how the filter should be remapped when it
  *   targets metadata-only columns. Note that this option is valid only if the column is numeric
  *   type.
- *       For example, a condition like {@code "msg.timestamp" > 1234} will be rewritten as
- *       {@code end_timestamp > 1234} to ensure metadata-based filtering produces a superset of the
- *       actual result.</li>
+ *       For example, a condition like {@code "msg.timestamp" > 1234 AND "msg.timestamp" < 5678}
+ *       will be rewritten as {@code end_timestamp > 1234 AND begin_timestamp < 5678} to ensure
+ *       metadata-based filtering produces a superset of the actual result.</li>
  * </ul>
  * <p>
  * This provider is used by {@code ClpFilterToKqlConverter} to determine which columns are eligible

presto-docs/src/main/sphinx/connector/clp.rst

@@ -29,6 +29,7 @@ following contents, modifying the properties as appropriate:
     clp.metadata-db-name=clp_db
     clp.metadata-db-user=clp_user
     clp.metadata-db-password=clp_password
+    clp.metadata-filter-config=/path/to/metadata-filter-config.json
     clp.metadata-table-prefix=clp_
     clp.split-provider-type=mysql
 
@@ -68,6 +69,7 @@ Property Name                      Description
                                    database name is not specified in the URL.
 ``clp.metadata-db-password``       The password for the metadata database user. This option is required if
                                    ``clp.metadata-provider-type`` is set to ``mysql``.
+``clp.metadata-filter-config``     The absolute path of the metadata filter config file.
 ``clp.metadata-table-prefix``      A string prefix prepended to all metadata table names when querying the
                                    database. Useful for namespacing or avoiding collisions. This option is
                                    required if ``clp.metadata-provider-type`` is set to ``mysql``.
@@ -94,6 +96,35 @@ If you prefer to use a different source--or the same source with a custom implem
 implementations of the ``ClpMetadataProvider`` and ``ClpSplitProvider`` interfaces, and configure the connector
 accordingly.
 
+Metadata Filter Config File
+----------------------------
+
+The configuration file defines metadata filters for different scopes:
+
+- **Catalog-level**: applies to all schemas and tables under the catalog.
+- **Schema-level**: applies to all tables under the specified catalog and schema.
+- **Table-level**: applies to the fully qualified ``catalog.schema.table``.
+
+Each scope maps to a list of filter definitions. Each filter includes:
+
+- ``filterName``: must match a column name in the table’s schema.
+
+  .. note::
+     Only numeric-type columns can currently be used as metadata filters.
+
+- ``rangeMapping`` *(optional)*: specifies how the filter should be remapped when it targets metadata-only columns.
+
+  .. note::
+     This option is only valid if the column is numeric type.
+
+  For example, a condition like:
+  ::
+     "msg.timestamp" > 1234 AND "msg.timestamp" < 5678
+  will be rewritten as:
+  ::
+     end_timestamp > 1234 AND begin_timestamp < 5678
+  This ensures that metadata-based filtering produces a superset of the actual result.
+
 Data Types
 ----------