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comparison src/main/java/org/monetdb/jdbc/MonetConnection.java @ 416:b3c876a0d61f

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Improved performance of ResultSetMetaData methods getSchemaName(), getTableName(), getPrecision(), getScale(), isNullable() and isAutoIncrement(). Previously getSchemaName() and getTableName() would extract the schema name or the table name from a single string containing both, separated by a dot. Now this is done once at a higher level (ResultSetResponse) and the values can be accessed directly. The methods getPrecision(), getScale(), isNullable() and isAutoIncrement() used to call fetchColumnInfo() which created a MonetDatabaseMetaData object and next call MonetDatabaseMetaData.getColumns() method. However this getColumns() method queries and returns much more info than really needed for the methods in ResultSetMetaData. It is a costly (and slow) method. Hence it is now replaced with a smaller and faster custom query (based on the query from getColumns()) which runs much faster. Also the creation of a MonetDatabaseMetaData object is no longer needed and has been removed.
author Martin van Dinther <martin.van.dinther@monetdbsolutions.com>
date Wed, 20 Jan 2021 23:54:03 +0100 (2021-01-20)
parents 1e278695fe54
children 8368cbc670bf
comparison
equal deleted inserted replaced
415:50e43af49d47 416:b3c876a0d61f
62 * The current state of this connection is that it nearly implements the 62 * The current state of this connection is that it nearly implements the
63 * whole Connection interface. 63 * whole Connection interface.
64 * 64 *
65 * @author Fabian Groffen 65 * @author Fabian Groffen
66 * @author Martin van Dinther 66 * @author Martin van Dinther
67 * @version 1.5 67 * @version 1.6
68 */ 68 */
69 public class MonetConnection 69 public class MonetConnection
70 extends MonetWrapper 70 extends MonetWrapper
71 implements Connection, AutoCloseable 71 implements Connection, AutoCloseable
72 { 72 {
2098 private String[] type; 2098 private String[] type;
2099 /** The max string length for each column in this result */ 2099 /** The max string length for each column in this result */
2100 private int[] columnLengths; 2100 private int[] columnLengths;
2101 /** The table for each column in this result */ 2101 /** The table for each column in this result */
2102 private String[] tableNames; 2102 private String[] tableNames;
2103 /** The schema for each column in this result */
2104 private String[] schemaNames;
2103 /** The query sequence number */ 2105 /** The query sequence number */
2104 private final int seqnr; 2106 private final int seqnr;
2105 /** A List of result blocks (chunks of size fetchSize/cacheSize) */ 2107 /** A List of result blocks (chunks of size fetchSize/cacheSize) */
2106 private DataBlockResponse[] resultBlocks; 2108 private DataBlockResponse[] resultBlocks;
2107 2109
2220 case HeaderLineParser.TYPE: 2222 case HeaderLineParser.TYPE:
2221 type = hlp.values.clone(); 2223 type = hlp.values.clone();
2222 isSet[TYPES] = true; 2224 isSet[TYPES] = true;
2223 break; 2225 break;
2224 case HeaderLineParser.TABLE: 2226 case HeaderLineParser.TABLE:
2227 {
2225 tableNames = hlp.values.clone(); 2228 tableNames = hlp.values.clone();
2229 final int array_size = tableNames.length;
2230 schemaNames = new String[array_size];
2231 // split the schema and table names from the cloned values array
2232 for (int i = 0; i < array_size; i++) {
2233 String qtable = tableNames[i];
2234 if (qtable != null) {
2235 int dot = qtable.indexOf('.');
2236 if (dot >= 0) {
2237 schemaNames[i] = qtable.substring(0, dot);
2238 tableNames[i] = qtable.substring(dot +1);
2239 } else {
2240 schemaNames[i] = "";
2241 }
2242 } else {
2243 schemaNames[i] = "";
2244 tableNames[i] = "";
2245 }
2246 }
2226 isSet[TABLES] = true; 2247 isSet[TABLES] = true;
2248 }
2227 break; 2249 break;
2228 } 2250 }
2229 } catch (MCLParseException e) { 2251 } catch (MCLParseException e) {
2230 return e.getMessage(); 2252 return e.getMessage();
2231 } 2253 }
2330 * 2352 *
2331 * @return the tables of the columns 2353 * @return the tables of the columns
2332 */ 2354 */
2333 String[] getTableNames() { 2355 String[] getTableNames() {
2334 return tableNames; 2356 return tableNames;
2357 }
2358
2359 /**
2360 * Returns the schemas of the columns
2361 *
2362 * @return the schemas of the columns
2363 */
2364 String[] getSchemaNames() {
2365 return schemaNames;
2335 } 2366 }
2336 2367
2337 /** 2368 /**
2338 * Returns the lengths of the columns 2369 * Returns the lengths of the columns
2339 * 2370 *