Changeset: ba852a4ec2ef for monetdb-java
URL: https://dev.monetdb.org/hg/monetdb-java/rev/ba852a4ec2ef
Modified Files:
src/main/java/org/monetdb/jdbc/MonetConnection.java
src/main/java/org/monetdb/jdbc/MonetPreparedStatement.java
Branch: default
Log Message:
Tweak fetchSize around PREPARE statements only when necessary
Older versions of MonetDB needed the reply size to be set to a large
value when a PREPARE statement was issued. In newer versions this
has been fixed so we can save some roundtrips.
diffs (125 lines):
diff --git a/src/main/java/org/monetdb/jdbc/MonetConnection.java
b/src/main/java/org/monetdb/jdbc/MonetConnection.java
--- a/src/main/java/org/monetdb/jdbc/MonetConnection.java
+++ b/src/main/java/org/monetdb/jdbc/MonetConnection.java
@@ -1963,6 +1963,63 @@ public class MonetConnection
return databaseMinorVersion;
}
+ private int databaseMicroVersion = 0;
+ /**
+ * Get the micro product version of the connected MonetDB Database
Server.
+ * The number is extracted from the env_monet_version the first time
and cached for next calls.
+ * It is called from: MonetDatabaseMetaData and MonetConnection
+ *
+ * @return the MonetDB Database Server minor version number.
+ * @throws SQLException if fetching MonetDB server version string failed
+ */
+ int getDatabaseMicroVersion() throws SQLException {
+ if (databaseMicroVersion == 0) {
+ if (env_monet_version == null)
+ getEnvValues();
+ if (env_monet_version != null) {
+ try {
+ // from version string such as 11.33.9
extract number: 9
+ int start =
env_monet_version.lastIndexOf('.'); // position of '.' or -1
+ start++;
+ databaseMicroVersion =
Integer.parseInt(env_monet_version.substring(start));
+ } catch (NumberFormatException nfe) {
+ // ignore
+ }
+ }
+ }
+ return databaseMicroVersion;
+ }
+
+ /**
+ * Utility method to check if connected server matches or is higher
than a requested version.
+ *
+ * @param requiredMajor dbserver requiredMajor version number.
+ * @param requiredMinor dbserver requiredMinor version number.
+ * @param requiredMicro dbserver requiredMicro version nimber
+ * @return true when the server version is higher or equal to the
requiredMajor.requiredMinor.requiredMicro else false.
+ */
+ boolean checkMinimumDBVersion(int requiredMajor, int requiredMinor, int
requiredMicro) {
+ try {
+ int serverMajor = getDatabaseMajorVersion();
+ if (serverMajor > requiredMajor)
+ return true;
+ if (serverMajor < requiredMajor)
+ return false;
+
+ int serverMinor = getDatabaseMinorVersion();
+ if (serverMinor > requiredMinor)
+ return true;
+ if (serverMinor < requiredMinor)
+ return false;
+
+ int serverMicro = getDatabaseMicroVersion();
+ return serverMicro >= requiredMicro;
+ } catch (SQLException e) {
+ // is this really the best way to handle this?
+ return false;
+ }
+ }
+
/**
* Utility method to check if connected server matches or is higher
than a requested version.
*
@@ -1971,11 +2028,7 @@ public class MonetConnection
* @return true when the server version is higher or equal to the
major.minor else false.
*/
boolean checkMinimumDBVersion(int major, int minor) {
- try {
- if ((getDatabaseMinorVersion() >= minor) &&
(getDatabaseMajorVersion() == major))
- return true;
- } catch (SQLException e) { /* ignore */ }
- return false;
+ return checkMinimumDBVersion(major, minor, 0);
}
/**
@@ -1990,6 +2043,29 @@ public class MonetConnection
return checkMinimumDBVersion(11, 47);
}
+ /**
+ * Older versions of MonetDB have a bug when PREPARE returns a large
descriptor,
+ * see https://github.com/MonetDB/MonetDB/issues/7622.
+ * In those versions fetchSize must be set to a very large number as a
workaround.
+ *
+ * @return true if the server supports arbitrarily large prepare
results and does
+ * not need the workaround.
+ */
+ boolean supportsLargePrepares() {
+ // Mar2025 has the fix starting from SP2
+ if (checkMinimumDBVersion(11, 53, 4))
+ return true;
+ // older Mar2025 release
+ if (checkMinimumDBVersion(11, 53, 0))
+ return false;
+
+ // Aug2024 has the fix starting from SP3
+ if (checkMinimumDBVersion(11, 51, 8))
+ return true;
+
+ // anything earlier doesn't have the fix (yet, as far as we
know)
+ return false;
+ }
// Internal cache for determining if system table sys.privilege_codes
(new as of Jul2017 release) exists on connected server
private boolean queriedPrivilege_codesTable = false;
diff --git a/src/main/java/org/monetdb/jdbc/MonetPreparedStatement.java
b/src/main/java/org/monetdb/jdbc/MonetPreparedStatement.java
--- a/src/main/java/org/monetdb/jdbc/MonetPreparedStatement.java
+++ b/src/main/java/org/monetdb/jdbc/MonetPreparedStatement.java
@@ -150,8 +150,9 @@ public class MonetPreparedStatement
*/
final int originalFetchSize = getFetchSize();
// increase the fetchSize temporarily before sending the
PREPARE statement
- // we can not use -1 (unlimited), so use a high value.
- setFetchSize(50*1000);
+ // we can not use -1 (unlimited), so use a very high value.
+ if (!connection.supportsLargePrepares())
+ setFetchSize(50*1000 * 1000);
if (!super.execute("PREPARE " + prepareQuery))
throw new SQLException("Unexpected server response",
"M0M10");
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