Mercurial > hg > monetdb-java
changeset 472:0e21097f438b
Reduce the number of MonetDatabaseMetaData objects created via getMetaData() to maximum 1 per connection as it can be reused.
| author | Martin van Dinther <martin.van.dinther@monetdbsolutions.com> |
|---|---|
| date | Fri, 30 Apr 2021 17:23:16 +0200 (2021-04-30) |
| parents | e14e81b8044e |
| children | 6a6c86ac3232 |
| files | src/main/java/org/monetdb/jdbc/MonetConnection.java |
| diffstat | 1 files changed, 9 insertions(+), 2 deletions(-) [+] |
line wrap: on
line diff
--- a/src/main/java/org/monetdb/jdbc/MonetConnection.java +++ b/src/main/java/org/monetdb/jdbc/MonetConnection.java @@ -147,6 +147,9 @@ public class MonetConnection /** The last set query timeout on the server as used by Statement, PreparedStatement and CallableStatement */ protected int lastSetQueryTimeout; // 0 means no timeout, which is the default on the server + /** A cache to reduce the number of DatabaseMetaData objects created by getMetaData() to maximum 1 per connection */ + private DatabaseMetaData dbmd; + /** * Constructor of a Connection for MonetDB. At this moment the @@ -586,10 +589,14 @@ public class MonetConnection */ @Override public DatabaseMetaData getMetaData() throws SQLException { + // for debug: System.out.println("calling getMetaData()"); if (lang != LANG_SQL) throw new SQLException("This method is only supported in SQL mode", "M0M04"); - - return new MonetDatabaseMetaData(this); + if (dbmd == null) { + // first use, construct it once and reuse it for all next calls + dbmd = new MonetDatabaseMetaData(this); + } + return dbmd; } /**