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Implementations use a group of arrays of equal size to store various attributes or cached instances of system tables.

Two fixed static lists of reserved table names are kept in String[] and HsqlName[] forms. These are shared by all implementations of DatabaseInformtion.

Each implementation keeps a lookup set of names for those tables whose contents are never cached (nonCachedTablesSet).

An instance of this class uses three lists named sysTablexxxx for caching system tables.

sysTableSessionDependent indicates which tables contain data that is dependent on the user rights of the User associatiod with the Session.

sysTableSessions contains the Session with whose rights each cached table was built.

sysTables contains the cached tables.

At the time of instantiation, which is part of the Database.open() method invocation, an empty table is created and placed in sysTables with calls to generateTable(int) for each name in sysTableNames. Some of these table entries may be null if an implementation does not produce them.

Calls to getSystemTable(String, Session) return a cached table if various caching rules are met (see below), or it will delete all rows of the table and rebuild the contents via generateTable(int).

generateTable(int) calls the appropriate single method for each table. These methods either build and return an empty table (if sysTables contains null for the table slot) or populate the table with up-to-date rows.

When the setDirty() call is made externally, the internal isDirty flag is set. This flag is used next time a call to getSystemTable(String, Session) is made.

Rules for caching are applied as follows:

When a call to getSystemTable(String, Session) is made, if the isDirty flag is true, then the contents of all cached tables are cleared and the sysTableUsers slot for all tables is set to null. This also has the effect of clearing the isDirty and isDirtyNextIdentity flags

if the isDirtyNextIdentity flag is true at this point, then the contents of all next identity value dependent cached tables are cleared and the sysTableUsers slot for these tables are set to null. Currently, the only member of this set is the SYSTEM_TABLES system table. If a table has non-cached contents, its contents are cleared and rebuilt.

For the rest of the tables, if the sysTableSessions slot is null or if the Session parameter is not the same as the Session object in that slot, the table contents are cleared and rebuilt.

(fredt@users)

author:
   boucherb@users
version:
   1.8.0
since:
   1.7.2

Each row is a column privilege description with the following columns:

 TABLE_CAT    VARCHAR   table catalog
 TABLE_SCHEM  VARCHAR   table schema
 TABLE_NAME   VARCHAR   table name
 COLUMN_NAME  VARCHAR   column name
 GRANTOR      VARCHAR   grantor of access
 GRANTEE      VARCHAR   grantee of access
 PRIVILEGE    VARCHAR   name of access
 IS_GRANTABLE VARCHAR   grantable?: "YES" - grant to others, else "NO"
 

Each row is an index column description with the following columns:

 TABLE_CAT        VARCHAR   table's catalog
 TABLE_SCHEM      VARCHAR   simple name of table's schema
 TABLE_NAME       VARCHAR   simple name of the table using the index
 NON_UNIQUE       BOOLEAN   can index values be non-unique?
 INDEX_QUALIFIER  VARCHAR   catalog in which the index is defined
 INDEX_NAME       VARCHAR   simple name of the index
 TYPE             SMALLINT  index type: { Clustered | Hashed | Other }
 ORDINAL_POSITION SMALLINT  column sequence number within index
 COLUMN_NAME      VARCHAR   simple column name
 ASC_OR_DESC      VARCHAR   col.

 TYPE_NAME          VARCHAR   the canonical name for DDL statements.
 DATA_TYPE          SMALLINT  data type code from DITypes.
 PRECISION          INTEGER   max column size.
 number => max precision.
 character => max characters.
 datetime => max chars incl.

Note: before 1.7.2 Alpha N, it was important to observe that by specifying an instance of this class or one of its descendents to handle system table production, the new set of builtin permissions and aliases would overwrite those of an existing database, meaning that metadata reporting might have been rendered less secure if the same database were then opened again using a lower numbered system table producer instance (i.e. one in a 1.7.1 or earlier distribution). As of 1.7.2 Alpha N, system-generated permissions and aliases are no longer recorded in the checkpoint script, obseleting this issue. Checkpointing of system-generated grants and aliases was removed because their existence is very close to a core requirment for correct operation and they are reintroduced to the system at each startup. In a future release, it may even be an exception condition to attempt to remove or alter system-generated grants and aliases, respectvely.

Parameters:
  db - the Database object for which this objectproduces system tables
throws:
  HsqlException - if a database access error occurs

 TYPE_NAME          VARCHAR   the canonical name used in DDL statements.
 DATA_TYPE          SMALLINT  data type code from Types
 PRECISION          INTEGER   max column size.
 number => max. precision.
 character => max characters.
 datetime => max chars incl. frac. component.
 LITERAL_PREFIX     VARCHAR   char(s) prefixing literal of this type.
 LITERAL_SUFFIX     VARCHAR   char(s) terminating literal of this type.
 CREATE_PARAMS      VARCHAR   Localized syntax-order list of domain
 create parameter keywords.
 - for human consumption only
 NULLABLE           SMALLINT  { No Nulls | Nullable | Unknown }
 CASE_SENSITIVE     BOOLEAN   case-sensitive in collations/comparisons?
 SEARCHABLE         SMALLINT  { None | Char (Only WHERE .. LIKE) |
 Basic (Except WHERE .. LIKE) |
 Searchable (All forms) }
 UNSIGNED_ATTRIBUTE BOOLEAN   { TRUE  (unsigned) | FALSE (signed) |
 NULL (non-numeric or not applicable) }
 FIXED_PREC_SCALE   BOOLEAN   { TRUE (fixed) | FALSE (variable) |
 NULL (non-numeric or not applicable) }
 AUTO_INCREMENT     BOOLEAN   automatic unique value generated for
 inserts and updates when no value or
 NULL specified?
 LOCAL_TYPE_NAME    VARCHAR   Localized name of data type;
 - NULL => not supported (no resource avail).
 - for human consumption only
 MINIMUM_SCALE      SMALLINT  minimum scale supported.
 MAXIMUM_SCALE      SMALLINT  maximum scale supported.
 SQL_DATA_TYPE      INTEGER   value expected in SQL CLI SQL_DESC_TYPE
 field of the SQLDA.
 SQL_DATETIME_SUB   INTEGER   SQL CLI datetime/interval subcode
 NUM_PREC_RADIX     INTEGER   numeric base w.r.t # of digits reported
 in PRECISION column (typically 10)
 INTERVAL_PRECISION INTEGER   interval leading precision (not implemented)
 AS_TAB_COL         BOOLEAN   type supported as table column?
 AS_PROC_COL        BOOLEAN   type supported as procedure column?
 MAX_PREC_ACT       BIGINT    like PRECISION unless value would be
 truncated using INTEGER
 MIN_SCALE_ACT      INTEGER   like MINIMUM_SCALE unless value would be
 truncated using SMALLINT
 MAX_SCALE_ACT      INTEGER   like MAXIMUM_SCALE unless value would be
 truncated using SMALLINT
 COL_ST_CLS_NAME    VARCHAR   Java Class FQN of in-memory representation
 COL_ST_IS_SUP      BOOLEAN   is COL_ST_CLS_NAME supported under the
 hosting JVM and engine build option?
 STD_MAP_CLS_NAME   VARCHAR   Java class FQN of standard JDBC mapping
 STD_MAP_IS_SUP     BOOLEAN   Is STD_MAP_CLS_NAME supported under the
 hosting JVM?
 CST_MAP_CLS_NAME   VARCHAR   Java class FQN of HSQLDB-provided JDBC
 interface representation
 CST_MAP_IS_SUP     BOOLEAN   is CST_MAP_CLS_NAME supported under the
 hosting JVM and engine build option?
 MCOL_JDBC          INTEGER   maximum character octet length representable
 via JDBC interface
 MCOL_ACT           BIGINT    like MCOL_JDBC unless value would be
 truncated using INTEGER
 DEF_OR_FIXED_SCALE INTEGER   default or fixed scale for numeric types
 REMARKS            VARCHAR   localized comment on the data type
 TYPE_SUB           INTEGER   From Types:
 {TYPE_SUB_DEFAULT | TYPE_SUB_IGNORECASE}
 deprecated: TYPE_SUB_IDENTITY
 

a Table object describing all of thestandard SQL types known to this database
throws:
  HsqlException - if an error occurs while producing the table

Each row describes a single column of the best row indentifier column set for a particular table. Each row has the following columns:

 SCOPE          SMALLINT  scope of applicability
 COLUMN_NAME    VARCHAR   simple name of the column
 DATA_TYPE      SMALLINT  SQL data type from Types
 TYPE_NAME      VARCHAR   canonical type name
 COLUMN_SIZE    INTEGER   precision
 BUFFER_LENGTH  INTEGER   transfer size in bytes, if definitely known
 DECIMAL_DIGITS SMALLINT  scale  - fixed # of decimal digits
 PSEUDO_COLUMN  SMALLINT  is this a pseudo column like an Oracle ROWID?
 TABLE_CAT      VARCHAR   table catalog
 TABLE_SCHEM    VARCHAR   simple name of table schema
 TABLE_NAME     VARCHAR   simple table name
 NULLABLE       SMALLINT  is column nullable?
 IN_KEY         BOOLEAN   column belongs to a primary or alternate key?
 

Notes:

jdbcDatabaseMetaData.getBestRowIdentifier uses its nullable parameter to filter the rows of this table in the following manner:

If the nullable parameter is false, then rows are reported only if, in addition to satisfying the other specified filter values, the IN_KEY column value is TRUE. If the nullable parameter is true, then the IN_KEY column value is ignored.

There is not yet infrastructure in place to make some of the ranking descisions described below, and it is anticipated that mechanisms upon which cost descisions could be based will change significantly over the next few releases. Hence, in the interest of simplicity and of not making overly complex dependency on features that will almost certainly change significantly in the near future, the current implementation, while perfectly adequate for all but the most demanding or exacting purposes, is actually sub-optimal in the strictest sense.

A description of the current implementation follows:

DEFINTIONS:

Alternate key

• An attribute of a table that, by virtue of its having a set of columns that are both the full set of columns participating in a unique constraint or index and are all not null, yeilds the same selectability characteristic that would obtained by declaring a primary key on those same columns.

Column set performance ranking

• The ranking of the expected average performance w.r.t a subset of a table's columns used to select and/or compare rows, as taken in relation to all other distinct candidate subsets under consideration. This can be estimated by comparing each cadidate subset in terms of total column count, relative peformance of comparisons amongst the domains of the columns and differences in other costs involved in the execution plans generated using each subset under consideration for row selection/comparison.

Rules:

Given the above definitions, the rules currently in effect for reporting best row identifier are as follows, in order of precedence:

1. if the table under consideration has a primary key contraint, then the columns of the primary key are reported, with no consideration given to the column set performance ranking over the set of candidate keys. Each row has its IN_KEY column set to TRUE.
2. if 1.) does not hold, then if there exits one or more alternate keys, then the columns of the alternate key with the lowest column count are reported, with no consideration given to the column set performance ranking over the set of candidate keys. If there exists a tie for lowest column count, then the columns of the first such key encountered are reported. Each row has its IN_KEY column set to TRUE.
3. if both 1.) and 2.) do not hold, then, if possible, a unique contraint/index is selected from the set of unique contraints/indices containing at least one column having a not null constraint, with no consideration given to the column set performance ranking over the set of all such candidate column sets. If there exists a tie for lowest non-zero count of columns having a not null constraint, then the columns of the first such encountered candidate set are reported. Each row has its IN_KEY column set to FALSE.

4. Finally, if the set of candidate column sets in 3.) is the empty, then no column set is reported for the table under consideration.

The scope reported for a best row identifier column set is determined thus:

1. if the database containing the table under consideration is in read-only mode or the table under consideration is GLOBAL TEMPORARY (a TEMP or TEMP TEXT table, in HSQLDB parlance), then the scope is reported as java.sql.DatabaseMetaData.bestRowSession.
2. if 1.) does not hold, then the scope is reported as java.sql.DatabaseMetaData.bestRowTemporary.

a Table object describing the optimalset of visible columns that uniquely identifies a rowfor each accessible table defined within this database
throws:
  HsqlException - if an error occurs while producing the table

Each row is a catalog name description with the following column:

 TABLE_CAT   VARCHAR   catalog name
 

a Table object naming the accessiblecatalogs defined within this database
throws:
  HsqlException - if an error occurs while producing the table

Definition:

 CREATE TABLE SYSTEM_CHECK_CONSTRAINTS (
 CONSTRAINT_CATALOG  VARCHAR NULL,
 CONSTRAINT_SCHEMA   VARCHAR NULL,
 CONSTRAINT_NAME     VARCHAR NOT NULL,
 CHECK_CLAUSE        VARCHAR NOT NULL,
 UNIQUE ( CONSTRAINT_CATALOG, CONSTRAINT_SCHEMA, CONSTRAINT_NAME )
 )
 

1. The values of CONSTRAINT_CATALOG, CONSTRAINT_SCHEMA and CONSTRAINT_NAME are the catalog name, unqualified schema name, and qualified identifier, respectively, of the constraint being described.

2. Case:

   a)	If the character representation of the <search condition> contained in the <check constraint definition>, <domain constraint definition>, or <assertion definition> that defined the check constraint being described can be represented without truncation, then the value of CHECK_CLAUSE is that character representation.
   b)	Otherwise, the value of CHECK_CLAUSE is the null value.

Each row is a column privilege description with the following columns:

 TABLE_CAT    VARCHAR   table catalog
 TABLE_SCHEM  VARCHAR   table schema
 TABLE_NAME   VARCHAR   table name
 COLUMN_NAME  VARCHAR   column name
 GRANTOR      VARCHAR   grantor of access
 GRANTEE      VARCHAR   grantee of access
 PRIVILEGE    VARCHAR   name of access
 IS_GRANTABLE VARCHAR   grantable?: "YES" - grant to others, else "NO"
 

a Table object describing the visibleaccess rights for all visible columns ofall accessible tables defined within thisdatabase
throws:
  HsqlException - if an error occurs while producing the table

Each row is a column description with the following columns:

 TABLE_CAT         VARCHAR   table catalog
 TABLE_SCHEM       VARCHAR   table schema
 TABLE_NAME        VARCHAR   table name
 COLUMN_NAME       VARCHAR   column name
 DATA_TYPE         SMALLINT  SQL type from DITypes
 TYPE_NAME         VARCHAR   canonical type name
 COLUMN_SIZE       INTEGER   column size (length/precision)
 BUFFER_LENGTH     INTEGER   transfer size in bytes, if definitely known
 DECIMAL_DIGITS    INTEGER   # of fractional digits (scale)
 NUM_PREC_RADIX    INTEGER   Radix
 NULLABLE          INTEGER   is NULL allowed? (from DatabaseMetaData)
 REMARKS           VARCHAR   comment describing column
 COLUMN_DEF        VARCHAR   default value (possibly expression)
 SQL_DATA_TYPE     VARCHAR   type code as expected in the SQL CLI SQLDA
 SQL_DATETIME_SUB  INTEGER   the SQL CLI subtype for DATETIME types
 CHAR_OCTET_LENGTH INTEGER   for char types, max # of bytes in column
 ORDINAL_POSITION  INTEGER   1-based index of column in table
 IS_NULLABLE       VARCHAR   is column nullable? ("YES"|"NO"|""}
 SCOPE_CATLOG      VARCHAR   catalog of REF attribute scope table
 SCOPE_SCHEMA      VARCHAR   schema of REF attribute scope table
 SCOPE_TABLE       VARCHAR   name of REF attribute scope table
 SOURCE_DATA_TYPE  VARCHAR   source type of REF attribute
 TYPE_SUB          INTEGER   HSQLDB data subtype code
 

a Table object describing thevisible columns of all accessibletables defined within this database.

throws:
  HsqlException - if an error occurs while producing the table

Each row is a foreign key column description with the following columns:

 PKTABLE_CAT   VARCHAR   referenced table catalog
 PKTABLE_SCHEM VARCHAR   referenced table schema
 PKTABLE_NAME  VARCHAR   referenced table name
 PKCOLUMN_NAME VARCHAR   referenced column name
 FKTABLE_CAT   VARCHAR   referencing table catalog
 FKTABLE_SCHEM VARCHAR   referencing table schema
 FKTABLE_NAME  VARCHAR   referencing table name
 FKCOLUMN_NAME VARCHAR   referencing column
 KEY_SEQ       SMALLINT  sequence number within foreign key
 UPDATE_RULE   SMALLINT
 { Cascade | Set Null | Set Default | Restrict (No Action)}?
 DELETE_RULE   SMALLINT
 { Cascade | Set Null | Set Default | Restrict (No Action)}?
 FK_NAME       VARCHAR   foreign key constraint name
 PK_NAME       VARCHAR   primary key or unique constraint name
 DEFERRABILITY SMALLINT
 { initially deferred | initially immediate | not deferrable }
 

a Table object describing how accessible tablesimport other accessible tables' primary key and/or uniqueconstraint columns
throws:
  HsqlException - if an error occurs while producing the table

Each row is an index column description with the following columns:

 TABLE_CAT        VARCHAR   table's catalog
 TABLE_SCHEM      VARCHAR   simple name of table's schema
 TABLE_NAME       VARCHAR   simple name of the table using the index
 NON_UNIQUE       BOOLEAN   can index values be non-unique?
 INDEX_QUALIFIER  VARCHAR   catalog in which the index is defined
 INDEX_NAME       VARCHAR   simple name of the index
 TYPE             SMALLINT  index type: { Clustered | Hashed | Other }
 ORDINAL_POSITION SMALLINT  column sequence number within index
 COLUMN_NAME      VARCHAR   simple column name
 ASC_OR_DESC      VARCHAR   col. sort sequence: {"A" (Asc) | "D" (Desc)}
 CARDINALITY      INTEGER   # of unique values in index (not implemented)
 PAGES            INTEGER   index page use (not implemented)
 FILTER_CONDITION VARCHAR   filter condition, if any (not implemented)
 // HSQLDB-extension
 ROW_CARDINALITY  INTEGER   total # of rows in index (not implemented)
 

a Table object describing the visibleIndex objects for each accessibletable defined within this database.
throws:
  HsqlException - if an error occurs while producing the table

Each row is a PRIMARY KEY column description with the following columns:

 TABLE_CAT   VARCHAR   table catalog
 TABLE_SCHEM VARCHAR   table schema
 TABLE_NAME  VARCHAR   table name
 COLUMN_NAME VARCHAR   column name
 KEY_SEQ     SMALLINT  sequence number within primary key
 PK_NAME     VARCHAR   primary key constraint name
 

a Table object describing the visibleprimary key columns of each accessible tabledefined within this database.
throws:
  HsqlException - if an error occurs while producing the table

Each row is a procedure column description with the following columns:

 PROCEDURE_CAT   VARCHAR   routine catalog
 PROCEDURE_SCHEM VARCHAR   routine schema
 PROCEDURE_NAME  VARCHAR   routine name
 COLUMN_NAME     VARCHAR   column/parameter name
 COLUMN_TYPE     SMALLINT  kind of column/parameter
 DATA_TYPE       SMALLINT  SQL type from DITypes
 TYPE_NAME       VARCHAR   SQL type name
 PRECISION       INTEGER   precision (length) of type
 LENGTH          INTEGER   transfer size, in bytes, if definitely known
 (roughly equivalent to BUFFER_SIZE for table
 columns)
 SCALE           SMALLINT  scale
 RADIX           SMALLINT  radix
 NULLABLE        SMALLINT  can column contain NULL?
 REMARKS         VARCHAR   explanatory comment on column
 SPECIFIC_NAME   VARCHAR   typically (but not restricted to) a
 fully qualified Java Method name and signature
 SEQ             INTEGER   The JDBC-specified order within
 runs of PROCEDURE_SCHEM, PROCEDURE_NAME,
 SPECIFIC_NAME, which is:
 return value (0), if any, first, followed
 by the parameter descriptions in call order
 (1..n1), followed by the result column
 descriptions in column number order
 (n1 + 1..n1 + n2)
 

a Table object describing thereturn, parameter and result columnsof the accessible routines definedwithin this database.
throws:
  HsqlException - if an error occurs while producing the table

 PROCEDURE_CAT     VARCHAR   catalog in which routine is defined
 PROCEDURE_SCHEM   VARCHAR   schema in which routine is defined
 PROCEDURE_NAME    VARCHAR   simple routine identifier
 NUM_INPUT_PARAMS  INTEGER   number of input parameters
 NUM_OUTPUT_PARAMS INTEGER   number of output parameters
 NUM_RESULT_SETS   INTEGER   number of result sets returned
 REMARKS           VARCHAR   explanatory comment on the routine
 PROCEDURE_TYPE    SMALLINT  { Unknown | No Result | Returns Result }
 ORIGIN            VARCHAR   {ALIAS |
 [BUILTIN | USER DEFINED] ROUTINE |
 [BUILTIN | USER DEFINED] TRIGGER |
 ...}
 SPECIFIC_NAME     VARCHAR   typically (but not restricted to) a
 fully qualified Java Method name
 and signature
 

a Table object describing the accessibleroutines defined within the this database
throws:
  HsqlException - if an error occurs while producing the table

Each row is a schema description with the following columns:

 TABLE_SCHEM      VARCHAR   simple schema name
 TABLE_CATALOG    VARCHAR   catalog in which schema is defined
 IS_DEFAULT       BOOLEAN   is the schema the default for new sessions
 

table containing information about schemas definedwithin this database
throws:
  HsqlException - if an error occurs while producing the table

Definition:

 CREATE TABLE SYSTEM_SEQUENCES (
 SEQUENCE_CATALOG     VARCHAR NULL,
 SEQUENCE_SCHEMA      VARCHAR NULL,
 SEQUENCE_NAME        VARCHAR NOT NULL,
 DTD_IDENTIFIER       VARCHAR NOT NULL,
 MAXIMUM_VALUE        VARCHAR NOT NULL,
 MINIMUM_VALUE        VARCHAR NOT NULL,
 INCREMENT            VARCHAR NOT NULL,
 CYCLE_OPTION         VARCHAR NOT NULL,
 START_WITH           VARCHAR NOT NULL,
 CHECK(CYCLE_OPTION IN('YES', 'NO')),
 CHECK(CAST(START_WITH AS BIGINT)
 BETWEEN CAST(MINIMUM_VALUE AS BIGINT)
 AND CAST(MAXIMUM_VALUE AS BIGINT)),
 UNIQUE(SEQUENCE_CATALOG, SEQUENCE_SCHEMA, SEQUENCE_NAME)
 )
 

1. The values of SEQUENCE_CATALOG, SEQUENCE_SCHEMA, and SEQUENCE_NAME are the catalog name, unqualified schema name, and qualified identifier, respectively, of the sequence generator being described.

2. The values of SEQUENCE_CATALOG, SEQUENCE_SCHEMA, SEQUENCE_NAME, and DTD_IDENTIFIER are the values of OBJECT_CATALOG, OBJECT_SCHEMA, OBJECT_NAME, and DTD_IDENTIFIER, respectively, of the row in DATA_TYPE_DESCRIPTOR (not yet implemented) that describes the data type of the sequence generator.

3. The values of MAXIMUM_VALUE, MINIMUM_VALUE, and INCREMENT are the character representations of maximum value, minimum value, and increment, respectively, of the sequence generator being described.

4. The values of CYCLE_OPTION have the following meanings:

   YES	The cycle option of the sequence generator is CYCLE.
   NO	The cycle option of the sequence generator is NO CYCLE.

5. The value of START_WITH is HSQLDB-specific (not in the SQL 200n spec).

   It is the character representation of the START WITH clause value that would be required to recreate or ALTER RESET START WITH the described SEQUENCE, such that its behaviour would be identical to that exhibited at the instant this table is materialized in the session context.

   In short, this is the character representation of value that would be generated by NEXT VALUE FOR at the instant this table is materialized in session context.

Each row is a table privilege description with the following columns:

 TABLE_CAT    VARCHAR   table catalog
 TABLE_SCHEM  VARCHAR   table schema
 TABLE_NAME   VARCHAR   table name
 GRANTOR      VARCHAR   grantor of access
 GRANTEE      VARCHAR   grantee of access
 PRIVILEGE    VARCHAR   { "SELECT" | "INSERT" | "UPDATE" | "DELETE" }
 IS_GRANTABLE VARCHAR   { "YES" | "NO" |  NULL (unknown) }
 

a Table object describing the visibleaccess rights for each accessible tabledefined within this database
throws:
  HsqlException - if an error occurs while producing the table

Each row is a table description with the following columns:

 TABLE_CAT                 VARCHAR   table catalog
 TABLE_SCHEM               VARCHAR   table schema
 TABLE_NAME                VARCHAR   table name
 TABLE_TYPE                VARCHAR   {"TABLE" | "VIEW" |
 "SYSTEM TABLE" | "GLOBAL TEMPORARY"}
 REMARKS                   VARCHAR   comment on the table.
 TYPE_CAT                  VARCHAR   table type catalog (not implemented).
 TYPE_SCHEM                VARCHAR   table type schema (not implemented).
 TYPE_NAME                 VARCHAR   table type name (not implemented).
 SELF_REFERENCING_COL_NAME VARCHAR   designated "identifier" column of
 typed table (not implemented).
 REF_GENERATION            VARCHAR   {"SYSTEM" | "USER" |
 "DERIVED" | NULL } (not implemented)
 HSQLDB_TYPE               VARCHAR   HSQLDB-specific type:
 {"MEMORY" | "CACHED" | "TEXT" | ...}
 READ_ONLY                 BOOLEAN   TRUE if table is read-only,
 else FALSE.
 

a Table object describing the accessibletables defined within this database
throws:
  HsqlException - if an error occurs while producing the table

In general, the range of values that may be commonly encounted across most DBMS implementations is:

• "TABLE"
• "VIEW"
• "SYSTEM TABLE"
• "GLOBAL TEMPORARY"
• "LOCAL TEMPORARY"
• "ALIAS"
• "SYNONYM"

As of HSQLDB 1.7.2, the engine supports and thus this method reports only a subset of the range above:

• "TABLE" (HSQLDB MEMORY, CACHED and TEXT tables)
• "VIEW" (Views)
• "SYSTEM TABLE" (The tables generated by this object)
• "GLOBAL TEMPORARY" (HSQLDB TEMP and TEMP TEXT tables)

a Table object describing the table typesavailable in this database
throws:
  HsqlException - if an error occurs while producing the table

 TYPE_NAME          VARCHAR   the canonical name for DDL statements.
 DATA_TYPE          SMALLINT  data type code from DITypes.
 PRECISION          INTEGER   max column size.
 number => max precision.
 character => max characters.
 datetime => max chars incl. frac. component.
 LITERAL_PREFIX     VARCHAR   char(s) prefixing literal of this type.
 LITERAL_SUFFIX     VARCHAR   char(s) terminating literal of this type.
 CREATE_PARAMS      VARCHAR   Localized syntax-order list of domain
 create parameter keywords.
 - for human consumption only
 NULLABLE           SMALLINT  {No Nulls | Nullable | Unknown}
 CASE_SENSITIVE     BOOLEAN   case-sensitive in collations/comparisons?
 SEARCHABLE         SMALLINT  {None | Char (Only WHERE .. LIKE) |
 Basic (Except WHERE .. LIKE) |
 Searchable (All forms)}
 UNSIGNED_ATTRIBUTE BOOLEAN   {TRUE  (unsigned) | FALSE (signed) |
 NULL (non-numeric or not applicable)}
 FIXED_PREC_SCALE   BOOLEAN   {TRUE (fixed) | FALSE (variable) |
 NULL (non-numeric or not applicable)}
 AUTO_INCREMENT     BOOLEAN   automatic unique value generated for
 inserts and updates when no value or
 NULL specified?
 LOCAL_TYPE_NAME    VARCHAR   localized name of data type;
 - NULL if not supported.
 - for human consuption only
 MINIMUM_SCALE      SMALLINT  minimum scale supported.
 MAXIMUM_SCALE      SMALLINT  maximum scale supported.
 SQL_DATA_TYPE      INTEGER   value expected in SQL CLI SQL_DESC_TYPE
 field of the SQLDA.
 SQL_DATETIME_SUB   INTEGER   SQL CLI datetime/interval subcode.
 NUM_PREC_RADIX     INTEGER   numeric base w.r.t # of digits reported in
 PRECISION column (typically 10).
 TYPE_SUB           INTEGER   From DITypes:
 {TYPE_SUB_DEFAULT | TYPE_SUB_IDENTITY |
 TYPE_SUB_IGNORECASE}
 

a Table object describing thesystem-defined SQL types supported as table columns
throws:
  HsqlException - if an error occurs while producing the table

Parameters:
  t - the table to which to add the specified column
Parameters:
  name - the name of the column
Parameters:
  type - the data type of the column
Parameters:
  size - the precision/length of the column
Parameters:
  nullable - true if the column is to allow null values,else false
throws:
  HsqlException - if a problem occurs when adding thecolumn (e.g. duplicate name)

Parameters:
  t - the table to which to add the specified column
Parameters:
  name - the name of the column
Parameters:
  type - the data type of the column
Parameters:
  nullable - true if the column is to allow null values,else false
throws:
  HsqlException - if a problem occurs when adding thecolumn (e.g. duplicate name)

Parameters:
  t - the table to which to add the specified column
Parameters:
  name - the name of the column
Parameters:
  type - the data type of the column
throws:
  HsqlException - if a problem occurs when adding thecolumn (e.g. duplicate name)

an enumeration over all of the tables in this database

throws:
  HsqlException - if a database access error occurs

a new system table
Parameters:
  name - of the table
throws:
  HsqlException - if a database access error occurs

Parameters:
  tableIndex - int value identifying the system table to generate
throws:
  HsqlException - if a database access error occurs the system table corresponding to the specified tableIndex value

Parameters:
  session - the Session object requesting the table
Parameters:
  name - a String identifying the desired table
throws:
  HsqlException - if there is a problem producing the table or adatabase access error occurs a system table corresponding to the name andsession arguments

throws:
  HsqlException - if a database access error occurs

true if the table is accessible, else false
Parameters:
  table - the table for which to check accessibility
throws:
  HsqlException - if a database access error occurs