pracro:database
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pracro:database [2008/11/25 09:00] – created deva | pracro:database [2010/06/07 11:17] (current) – deva | ||
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======Pracro Database design====== | ======Pracro Database design====== | ||
- | Nothing to see here, move along.... | + | Nothing to see here, move along... |
+ | |||
+ | =====Persistent transactions===== | ||
+ | When a new Pracro session is initiated, a connection to PostgreSQL is made. | ||
+ | All commands (strings) issued to this connection, will be appended to a string contained in the session class. | ||
+ | This string will be serialised with the rest of the session data upon pracrod shutdown and re-read on startup. | ||
+ | The first SQL command issued is BEGIN; | ||
+ | If a ' | ||
+ | If the client disconnects without any actions, an ROLLBACK; is sent to the SQL server. | ||
+ | On reconnect to the session, the entire command string is replayed as it is, and the session is ready to continue where it left off. | ||
+ | On the Pracro ' | ||
+ | |||
+ | =====Journal uptodateness check===== | ||
+ | * Person A is working on a patient P. | ||
+ | * Person A commits the macro M, with data "data from A". | ||
+ | * Person A 'close no commit' | ||
+ | * Person B starts working on patient P. | ||
+ | * Person B commits the macro M, with data "data from B". | ||
+ | * Person B 'close and commit' | ||
+ | * Person A continues work on patient P. | ||
+ | * Person A sees the resume of M being "data from B", and acknowledges it. | ||
+ | * Person A 'close and commit' | ||
+ | Person A now **thinks** that the journal contains "data from B". But in fact it contains | ||
+ | < | ||
+ | data from B | ||
+ | data from A | ||
+ | </ | ||
+ | This is due to two problems: The field shown on the active session is not nesecarily the one being commit, when the entire session is committed. Second person A cannot see what changes has been made by others. |
pracro/database.txt · Last modified: 2010/06/07 11:17 by deva