Changeset: 6e48d0fae766 for monetdb-java URL: https://dev.monetdb.org/hg/monetdb-java/rev/6e48d0fae766 Modified Files: ChangeLog src/main/java/nl/cwi/monetdb/jdbc/MonetDatabaseMetaData.java Branch: default Log Message:
Corrected return values of DatabaseMetaData methods nullsAreSortedHigh(), nullsAreSortedLow(), getMaxCursorNameLength(), getMaxProcedureNameLength(), getMaxStatementLength() and getMaxUserNameLength(). Improved return values of DatabaseMetaData methods getMaxBinaryLiteralLength(), getMaxCharLiteralLength() and getMaxColumnsInTable(). diffs (truncated from 332 to 300 lines): diff --git a/ChangeLog b/ChangeLog --- a/ChangeLog +++ b/ChangeLog @@ -2,6 +2,11 @@ # This file is updated with Maddlog * Thu Oct 6 2016 Martin van Dinther <[email protected]> +- Corrected return values of DatabaseMetaData methods nullsAreSortedHigh(), + nullsAreSortedLow(), getMaxCursorNameLength(), getMaxProcedureNameLength(), + getMaxStatementLength() and getMaxUserNameLength(). + Improved return values of DatabaseMetaData methods getMaxBinaryLiteralLength(), + getMaxCharLiteralLength() and getMaxColumnsInTable(). - Implemented Statement methods: getQueryTimeout() and setQueryTimeout(int seconds). getQueryTimeout() used to always return 0, now it returns the query timeout retrieved from the server. setQueryTimeout(int seconds) diff --git a/src/main/java/nl/cwi/monetdb/jdbc/MonetDatabaseMetaData.java b/src/main/java/nl/cwi/monetdb/jdbc/MonetDatabaseMetaData.java --- a/src/main/java/nl/cwi/monetdb/jdbc/MonetDatabaseMetaData.java +++ b/src/main/java/nl/cwi/monetdb/jdbc/MonetDatabaseMetaData.java @@ -163,24 +163,32 @@ public class MonetDatabaseMetaData exten } /** - * Are NULL values sorted high? + * Retrieves whether NULL values are sorted high. Sorted high means + * that NULL values sort higher than any other value in a domain. + * In an ascending order, if this method returns true, NULL values will appear at the end. + * By contrast, the method nullsAreSortedAtEnd indicates whether NULL values are sorted at the end regardless of sort order. * - * @return true because MonetDB puts NULL values on top upon ORDER BY + * @return false because MonetDB shows NULL values at the beginning upon ORDER BY .. ASC */ @Override public boolean nullsAreSortedHigh() { - return true; + return false; } /** - * Are NULL values sorted low? + * Retrieves whether NULL values are sorted low. Sorted low means + * that NULL values sort lower than any other value in a domain. + * In an ascending order, if this method returns true, NULL values will appear at the beginning. + * By contrast, the method nullsAreSortedAtStart indicates whether NULL values are sorted at the beginning regardless of sort order. + * + * @return true because MonetDB shows NULL values at the beginning upon ORDER BY .. ASC * * @return negative of nullsAreSortedHigh() * @see #nullsAreSortedHigh() */ @Override public boolean nullsAreSortedLow() { - return !nullsAreSortedHigh(); + return true; } /** @@ -269,8 +277,8 @@ public class MonetDatabaseMetaData exten } /** - * Does the database store tables in a local file? No - it - * stores them in a file on the server. + * Does the database store tables in a local file? + * No, it stores them in files on the server. * * @return false because that's what MonetDB is for */ @@ -280,8 +288,7 @@ public class MonetDatabaseMetaData exten } /** - * Does the database use a local file for each table? Well, not really, - * since it doesn't use local files. + * Does the database use a local file for each table? * * @return false for it doesn't */ @@ -965,7 +972,7 @@ public class MonetDatabaseMetaData exten } /** - * Are full nexted outer joins supported? + * Are full nested outer joins supported? * * @return true if so */ @@ -1315,24 +1322,22 @@ public class MonetDatabaseMetaData exten /** * How many hex characters can you have in an inline binary literal - * I honestly wouldn't know... * * @return the max literal length */ @Override public int getMaxBinaryLiteralLength() { - return 0; // no limit + return 2*1024*1024*1024 - 2; // MonetDB supports null terminated strings of max 2GB, see function: int UTF8_strlen() } /** * What is the maximum length for a character literal - * Is there a max? * * @return the max literal length */ @Override public int getMaxCharLiteralLength() { - return 0; // no limit + return 2*1024*1024*1024 - 2; // MonetDB supports null terminated strings of max 2GB, see function: int UTF8_strlen() } /** @@ -1343,7 +1348,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxColumnNameLength() { - return 1024; + return 1024; // In MonetDB the max length of column sys._columns.name is defined as 1024 } /** @@ -1353,7 +1358,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxColumnsInGroupBy() { - return 0; // no limit + return 0; // no specific limit known } /** @@ -1363,7 +1368,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxColumnsInIndex() { - return 0; // unlimited I guess + return 0; // no specific limit known } /** @@ -1373,7 +1378,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxColumnsInOrderBy() { - return 0; // unlimited I guess + return 0; // no specific limit known } /** @@ -1383,18 +1388,21 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxColumnsInSelect() { - return 0; // unlimited I guess + return 0; // no specific limit known } /** * What is the maximum number of columns in a table? - * wasn't MonetDB designed for datamining? (= much columns) + * + * The theoretical max value of int column sys._columns.id is 2^31 -1 + * but this is for all columns of all tables in all schemas (including all data dictionary columns). + * For one table we should reduce it to a more practical soft limit of say 100 thousand * * @return the max columns */ @Override public int getMaxColumnsInTable() { - return 0; + return 100*1000; // soft limit it to 100 thousand } /** @@ -1431,7 +1439,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxCursorNameLength() { - return 1024; + return 0; // no specific limit known } /** @@ -1444,7 +1452,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxIndexLength() { - return 0; // I assume it is large, but I don't know + return 0; // no specific limit known } /** @@ -1456,7 +1464,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxSchemaNameLength() { - return 1024; + return 1024; // In MonetDB the max length of column sys.schemas.name is defined as 1024 } /** @@ -1466,7 +1474,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxProcedureNameLength() { - return 1024; + return 256; // In MonetDB the max length of column sys.functions.name is defined as 256 } /** @@ -1491,7 +1499,7 @@ public class MonetDatabaseMetaData exten } /** - * Did getMaxRowSize() include LONGVARCHAR and LONGVARBINARY + * Did getMaxRowSize() include the SQL data types LONGVARCHAR and LONGVARBINARY * blobs? * Yes I thought so... * @@ -1504,14 +1512,12 @@ public class MonetDatabaseMetaData exten /** * What is the maximum length of a SQL statement? - * Till a programmer makes a mistake and causes a segmentation fault - * on a string overflow... * * @return max length in bytes */ @Override public int getMaxStatementLength() { - return 0; // actually whatever fits in size_t + return 2*1024*1024*1024 - 2; // MonetDB supports null terminated strings of max 2GB, see function: int UTF8_strlen() } /** @@ -1523,7 +1529,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxStatements() { - return 0; + return 0; // no specific limit known } /** @@ -1533,7 +1539,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxTableNameLength() { - return 1024; + return 1024; // In MonetDB the max length of column sys._tables.name is defined as 1024 } /** @@ -1544,7 +1550,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxTablesInSelect() { - return 0; // no limit + return 0; // no specific limit known } /** @@ -1554,7 +1560,7 @@ public class MonetDatabaseMetaData exten */ @Override public int getMaxUserNameLength() { - return 512; + return 1024; // In MonetDB the max length of column sys.db_user_info.name is defined as 1024 } /** @@ -2153,7 +2159,7 @@ public class MonetDatabaseMetaData exten * <UL> * <LI> YES --- if the column is auto incremented * <LI> NO --- if the column is not auto incremented - * <LI> empty string --- if it cannot be determined whether the column is auto incremented + * <LI> empty string --- if it cannot be determined whether the column is auto incremented * </UL> * <LI><B>IS_GENERATEDCOLUMN</B> String => Indicates whether this is a generated column * <UL> @@ -3527,7 +3533,7 @@ public class MonetDatabaseMetaData exten * scope of a reference attribute (<code>null</code> if DATA_TYPE isn't REF) * <LI><B>SCOPE_TABLE</B> String => table name that is the scope of a * reference attribute (<code>null</code> if the DATA_TYPE isn't REF) - * <LI><B>SOURCE_DATA_TYPE</B> short => source type of a distinct type or user-generated + * <LI><B>SOURCE_DATA_TYPE</B> short => source type of a distinct type or user-generated * Ref type,SQL type from java.sql.Types (<code>null</code> if DATA_TYPE * isn't DISTINCT or user-generated REF) * </OL> @@ -3617,7 +3623,7 @@ public class MonetDatabaseMetaData exten // ignore } } - return major; + return major; } /** @@ -3643,7 +3649,7 @@ public class MonetDatabaseMetaData exten // ignore _______________________________________________ checkin-list mailing list [email protected] https://www.monetdb.org/mailman/listinfo/checkin-list
