Tables Count

The stats show the evolution of the database with respect to the number of tables for each revision; The number of revision in the graph is a progessive number, the correspondent revision number is located in the attached csv file

SELECT d.svn_version, count(*) FROM PRISM_TABLES t,PRISM_VERSIONS d WHERE t.table_schema = d.schema_unique_name and t.table_schema like ? GROUP BY d.svn_version ORDER BY d.tstart

Table Added and Deleted

The statistic show the number of tables added and deleted every change of revision; The tables count statistic doesn't show the detail of the transition between one revision and the other, while in this way it is possibile to better understand the change between the revisions looking into the modifications occured to the database schema

The sql compare the name of the tables of every revision with the table name of the previuos and following revision

Rolledback tables

The statistic analyze the evolution's story of the table, looking into possible situations of rollbacks; a "rollback" occurs when a situation like the one described here occurs: at the time n-1 the table has a structure x; then at the time n, the table is modified by the database administratorchanging his structure; the new structure is called y; the database evolvs and the db admin decide, at the time n+1, to change again the structure of the table into x;the table has undergone a rollback changing its structure from x to y and then back to x again

The sql analyze the structure, in terms of columns, of the table during each revision comparing it with the structure of the revision + 1; creates a checkpoint every change of structure and then analyze each checkpointlooking for possible rollback situations

Tables Lifetime

The statistics show the lifetimes of each table: the life of a table is the number of revision where the table is presentit doesn't necessary mean the table was live for consecutive revisions, this is just a qualitative chart to represent the number of revision where table was present

SELECT TABLE_NAME, COUNT(*) FROM PRISM_TABLES WHERE TABLE_SCHEMA LIKE ? GROUP BY TABLE_NAME ORDER BY count(*) DESC