gudusoft.gsqlparser.sqlenv

Class TemporaryTableSemantics

Object

gudusoft.gsqlparser.sqlenv.TemporaryTableSemantics

public final class TemporaryTableSemantics
extends Object

Who can see a temporary table's definition, per vendor and declaration form.

This is the one place that decides it. resolver2 binds each table reference to the definition this rule makes visible there, and the lineage model shares a table model exactly when resolver2 bound two references to the same definition, so lookup and publish follow one rule.

A table whose definition is transient belongs to the routine body (or the top-level script) that creates it. Parsing a routine is not running it, so another routine never sees that definition unless a call in the analyzed SQL proves it can:

• TemporaryTableSemantics.Scope.CALL: the routine that creates the table and the routines it calls, until it returns.
• TemporaryTableSemantics.Scope.SESSION: as CALL, and the table also outlives the routine, so after the call its caller sees it too.

TemporaryTableSemantics.Scope.CATALOG and TemporaryTableSemantics.Scope.GLOBAL definitions are shared by every routine, as a permanent table's is.

Vendor rules, from each vendor's documentation:

• SQL Server, Azure SQL: #name is CALL ("Temporary tables" in CREATE TABLE); ##name is GLOBAL, one live object for every session.
• SAP ASE: #name is CALL; ASE has no ## form, so ##name is another # table. CREATE GLOBAL TEMPORARY TABLE is CATALOG.
• SAP IQ, SQL Anywhere: a #name table created in a procedure outlives it (running the procedure again fails with "table already exists"), so it is SESSION, as is CREATE LOCAL TEMPORARY TABLE. CREATE GLOBAL TEMPORARY TABLE is CATALOG. dbvsybase names no single product and follows IQ.
• SAP HANA: a local temporary table (#name) is SESSION; a global temporary table is CATALOG.
• PostgreSQL, Greenplum, Redshift: TEMP/TEMPORARY is SESSION; GLOBAL and LOCAL are accepted and ignored, so they are SESSION too. Redshift #name is SESSION.
• MySQL, BigQuery, Netezza: TEMPORARY/TEMP is SESSION.
• Snowflake: TEMPORARY and its synonyms (LOCAL, GLOBAL, VOLATILE) are SESSION. A procedure's CREATE PROCEDURE SCOPED TEMP TABLE is not classified: GSP does not parse it yet.
• Teradata: VOLATILE is SESSION; GLOBAL TEMPORARY is CATALOG.
• Oracle: GLOBAL TEMPORARY is CATALOG; PRIVATE TEMPORARY is SESSION.
• Vertica: LOCAL TEMPORARY is SESSION; GLOBAL TEMPORARY is CATALOG, and so is plain TEMPORARY, which is global under Vertica's default DefaultTempTableLocal = 0 (a server configured with 1 makes it local).
• Db2: CREATE GLOBAL TEMPORARY TABLE is CATALOG.
• GaussDB, EDB: TEMP/LOCAL TEMP is SESSION; GLOBAL TEMPORARY is CATALOG.

Any other vendor or form is not classified (null): its tables are analyzed as permanent tables are.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TemporaryTableSemantics.Scope Who can see a temporary table's definition.

Method Summary

Modifier and Type	Method and Description
static boolean	hasTransientTables(EDbVendor vendor) Whether vendor has any transient temporary tables, so routine bodies need their own scope.
static boolean	isTransient(TemporaryTableSemantics.Scope scope) Whether a definition of this scope belongs to the body that creates it.
static boolean	isTransientName(EDbVendor vendor, TObjectName name) Whether a table name alone makes it transient (#name in the vendors that read it so).
static TemporaryTableSemantics.Scope	ofDeclaration(TCreateTableSqlStatement create) The scope of the table a CREATE TABLE statement declares, or null for a permanent table.
static TemporaryTableSemantics.Scope	ofKinds(EDbVendor vendor, Collection<ETableKind> kinds) The scope the declaration keywords (TEMPORARY, VOLATILE ...) give a table.
static TemporaryTableSemantics.Scope	ofName(EDbVendor vendor, TObjectName name) The scope a table's name alone gives it, from its SQL-lexical object segment.
static TemporaryTableSemantics.Scope	ofNameSegment(EDbVendor vendor, String lexicalObjectSegment) The scope a table's name alone gives it, from one SQL-lexical object segment.
static TemporaryTableSemantics.Scope	ofSelectInto(EDbVendor vendor, TObjectName target) The scope of the table a {@code SELECT ...
static TemporaryTableSemantics.Scope	ofStoredName(EDbVendor vendor, String storedName) The scope a stored (decoded) table name alone gives it, or null when the name says nothing.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isTransient

public static boolean isTransient(TemporaryTableSemantics.Scope scope)

Whether a definition of this scope belongs to the body that creates it.

ofName

public static TemporaryTableSemantics.Scope ofName(EDbVendor vendor,
                                                   TObjectName name)

The scope a table's name alone gives it, from its SQL-lexical object segment.

ofNameSegment

public static TemporaryTableSemantics.Scope ofNameSegment(EDbVendor vendor,
                                                          String lexicalObjectSegment)

The scope a table's name alone gives it, from one SQL-lexical object segment.

ofStoredName

public static TemporaryTableSemantics.Scope ofStoredName(EDbVendor vendor,
                                                         String storedName)

The scope a stored (decoded) table name alone gives it, or null when the name says nothing.

ofKinds

public static TemporaryTableSemantics.Scope ofKinds(EDbVendor vendor,
                                                    Collection<ETableKind> kinds)

The scope the declaration keywords (TEMPORARY, VOLATILE ...) give a table.

ofDeclaration

public static TemporaryTableSemantics.Scope ofDeclaration(TCreateTableSqlStatement create)

The scope of the table a CREATE TABLE statement declares, or null for a permanent table.

ofSelectInto

public static TemporaryTableSemantics.Scope ofSelectInto(EDbVendor vendor,
                                                         TObjectName target)

The scope of the table a SELECT ... INTO target creates (INTO #t, INTO TEMP t), or null for a permanent table. SAP HANA's SELECT ... INTO assigns variables and creates no table, so a HANA target never has one.

isTransientName

public static boolean isTransientName(EDbVendor vendor,
                                      TObjectName name)

Whether a table name alone makes it transient (#name in the vendors that read it so).

hasTransientTables

public static boolean hasTransientTables(EDbVendor vendor)

Whether vendor has any transient temporary tables, so routine bodies need their own scope.