Sybase 12.4.2 manual Multiple writers and readers in a database, 294

Overview of transactions and versioning

Figure 8-2: One writer, multiple readers

Multiple writers and readers in a database

Within an IQ database that is not multiplex, multiple read-only and read/write users can operate concurrently, as long as the writers are inserting data into (or deleting it from) different tables. So, for example, while User 1’s transaction is inserting and deleting in the customer table, User 2 can begin a transaction that loads data into the employee table, as shown in Figure 8-3. At the same time other users can execute transactions that issue queries to both of these tables, or to any other tables in the database.

In an IQ Multiplex database, read/write users must all connect to the write server, whereas read-only users can connect to any query server or the write server. For more information, see Adaptive Server IQ Multiplex User’s Guide.

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