support drop index for Lucene full-text indices

h2/src/docsrc/html/changelog.html

@@ -49,6 +49,7 @@ Change Log
 </li><li>Improved OSGi support. H2 now registers itself as a DataSourceFactory service. Fixes issue 365.
 </li><li>Add a DISK_SPACE_USED system function. Fixes issue 270.
 </li><li>Fix a compile-time ambiguity when compiling with JDK7, thanks to a patch from Lukas Eder.
+</li><li>Supporting dropping an index for Lucene full-text indexes.
 </li></ul>
 
 <h2>Version 1.3.170 (2012-11-30)</h2>

h2/src/docsrc/html/tutorial.html

@@ -1215,6 +1215,12 @@ This will produce a result set that contains the query needed to retrieve the da
 QUERY: "PUBLIC"."TEST" WHERE "ID"=1
 </pre>
 <p>
+To drop an index on a table:
+</p>
+<pre>
+CALL FT_DROP_INDEX('PUBLIC', 'TEST');
+</pre>
+<p>
 To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code>.
 The result contains the columns <code>SCHEMA</code> (the schema name),
 <code>TABLE</code> (the table name),
@@ -1270,6 +1276,13 @@ This will produce a result set that contains the query needed to retrieve the da
 QUERY: "PUBLIC"."TEST" WHERE "ID"=1
 </pre>
 <p>
+To drop an index on a table:
+(be warned that this will re-index all of the full-text indices for the entire database)
+</p>
+<pre>
+CALL FTL_DROP_INDEX('PUBLIC', 'TEST');
+</pre>
+<p>
 To get the raw data, use <code>FTL_SEARCH_DATA('Hello', 0, 0);</code>.
 The result contains the columns <code>SCHEMA</code> (the schema name),
 <code>TABLE</code> (the table name),

h2/src/main/org/h2/fulltext/FullTextLucene.java

@@ -106,6 +106,7 @@ public class FullTextLucene extends FullText {
         stat.execute("CREATE TABLE IF NOT EXISTS " + SCHEMA
                         + ".INDEXES(SCHEMA VARCHAR, TABLE VARCHAR, COLUMNS VARCHAR, PRIMARY KEY(SCHEMA, TABLE))");
         stat.execute("CREATE ALIAS IF NOT EXISTS FTL_CREATE_INDEX FOR \"" + FullTextLucene.class.getName() + ".createIndex\"");
+        stat.execute("CREATE ALIAS IF NOT EXISTS FTL_DROP_INDEX FOR \"" + FullTextLucene.class.getName() + ".dropIndex\"");
         stat.execute("CREATE ALIAS IF NOT EXISTS FTL_SEARCH FOR \"" + FullTextLucene.class.getName() + ".search\"");
         stat.execute("CREATE ALIAS IF NOT EXISTS FTL_SEARCH_DATA FOR \"" + FullTextLucene.class.getName() + ".searchData\"");
         stat.execute("CREATE ALIAS IF NOT EXISTS FTL_REINDEX FOR \"" + FullTextLucene.class.getName() + ".reindex\"");
@@ -138,6 +139,29 @@ public class FullTextLucene extends FullText {
         indexExistingRows(conn, schema, table);
     }
 
+    /**
+     * Drop an existing full text index for a table. This method returns
+     * silently if no index for this table exists.
+     *
+     * @param conn the connection
+     * @param schema the schema name of the table (case sensitive)
+     * @param table the table name (case sensitive)
+     */
+    public static void dropIndex(Connection conn, String schema, String table) throws SQLException {
+        init(conn);
+        
+        PreparedStatement prep = conn.prepareStatement("DELETE FROM " + SCHEMA
+                + ".INDEXES WHERE SCHEMA=? AND TABLE=?");
+        prep.setString(1, schema);
+        prep.setString(2, table);
+        int rowCount = prep.executeUpdate();
+        if (rowCount == 0) {
+            return;
+        }
+
+        reindex(conn);
+    }
+    
     /**
      * Re-creates the full text index for this database. Calling this method is
      * usually not needed, as the index is kept up-to-date automatically.
@@ -233,9 +257,15 @@ public class FullTextLucene extends FullText {
      * @param table the table name
      */
     protected static void createTrigger(Connection conn, String schema, String table) throws SQLException {
+        createOrDropTrigger(conn, schema, table, true);
+    }
+    
+    private static void createOrDropTrigger(Connection conn,
+            String schema, String table, boolean create) throws SQLException {
         Statement stat = conn.createStatement();
         String trigger = StringUtils.quoteIdentifier(schema) + "." + StringUtils.quoteIdentifier(TRIGGER_PREFIX + table);
         stat.execute("DROP TRIGGER IF EXISTS " + trigger);
+        if (create) {
             StringBuilder buff = new StringBuilder("CREATE TRIGGER IF NOT EXISTS ");
             // the trigger is also called on rollback because transaction rollback
             // will not undo the changes in the Lucene index
@@ -249,6 +279,7 @@ public class FullTextLucene extends FullText {
                 append('\"');
             stat.execute(buff.toString());
         }
+    }
 
     /**
      * Get the index writer/searcher wrapper for the given connection.