GUACAMOLE-1253: Update select all queries to process in batches.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/conf/PostgreSQLEnvironment.java

@@ -115,6 +115,18 @@ public class PostgreSQLEnvironment extends JDBCEnvironment {
      * The default value to use for SSL mode if none is explicitly configured.
      */
     private final PostgreSQLSSLMode DEFAULT_SSL_MODE = PostgreSQLSSLMode.PREFER;
+    
+    /**
+     * The default maximum number of identifiers/parameters to be included in a 
+     * single batch when executing SQL statements for PostgreSQL.
+     * 
+     * PostgreSQL has a maximum limit of 65535 parameters per prepared statement.
+     * A value of 5000 is chosen to avoid potential performance issues or query
+     * execution errors while staying well below the maximum limit.
+     *
+     * @see https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAX-PREPARED-STATEMENT-ARGS
+     */
+    private static final int DEFAULT_BATCH_SIZE = 5000;
 
     /**
      * Constructs a new PostgreSQLEnvironment, providing access to PostgreSQL-specific
@@ -146,6 +158,13 @@ public class PostgreSQLEnvironment extends JDBCEnvironment {
         );
     }
 
+    @Override
+    public int getBatchSize() throws GuacamoleException {
+        return getProperty(PostgreSQLGuacamoleProperties.POSTGRESQL_BATCH_SIZE,
+            DEFAULT_BATCH_SIZE
+        );
+    }    
+    
     @Override
     public int getDefaultMaxConnections() throws GuacamoleException {
         return getProperty(

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/conf/PostgreSQLGuacamoleProperties.java

@@ -277,4 +277,16 @@ public class PostgreSQLGuacamoleProperties {
                 
     };
     
+    /**
+     * The maximum number of identifiers/parameters to be included in a single batch when
+     * executing SQL statements.
+     */
+    public static final IntegerGuacamoleProperty POSTGRESQL_BATCH_SIZE =
+            new IntegerGuacamoleProperty() {
+
+        @Override
+        public String getName() { return "postgresql-batch-size"; }
+
+    };
+
 }