VbzCart/tables/cache flow

About

 * Purpose: Keeps track of data dependencies between tables – which queries update cached data in which tables from which sources
 * Used by :
 * Refers to: ,
 * Fields:
 * doWrite: TRUE = ID_Table is written to (i.e. TARGET table); otherwise it is only read from (SOURCE).
 * Notes:
 * If it turns out that some tables are both read and written, then we might want a doRead field as well.
 * History:
 * 2010-11-09 Renamed data_flow -> cache_flow; ID_Proc -> ID_Query
 * 2010-11-13 Significant revision: ID_Srce/ID_Dest replaced by ID_Table/doWrite

SQL
CREATE TABLE `cache_flow` (   ID_Proc INT NOT NULL COMMENT "cache_queries.ID of stored procedure which calculates Dest data from Srce data",    ID_Table INT NOT NULL COMMENT "cache_tables.ID of a table",    doWrite BOOL COMMENT "TRUE = writes to this table",    Notes   VARCHAR(255) COMMENT "loose explanatory or descriptive notes",    PRIMARY KEY (`ID_Query`,`ID_Table`) ) ENGINE = MYISAM;

previous version
CREATE TABLE `cache_flow` (   ID_Srce INT NOT NULL COMMENT "cache_tables.ID of SOURCE table",    ID_Dest INT NOT NULL COMMENT "cache_tables.ID of DESTINATION table",    ID_Query INT NOT NULL COMMENT "cache_queries.ID of stored procedure which calculates Dest data from Srce data",    Notes   VARCHAR(255) COMMENT "loose explanatory or descriptive notes",    PRIMARY KEY (`ID_Srce`,`ID_Dest`,`ID_Query`) ) ENGINE = MYISAM;