VbzCart/tables/cache flow

About

• Purpose: Keeps track of data dependencies between tables – which queries update cached data in which tables from which sources
• Refers to: cache_tables, cache_queries
• 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

<mysql>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;</mysql>

previous version

<mysql>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;</mysql>