Online data migration
First Claim
1. A computer-implemented method comprising:
- migrating data during uptime from a first table to a second table in a first schema in a database, a first application server connecting to the database using the first schema, a second application server connecting to the database using a second schema, the first application server running a first version of a software program, the second application server running a second version of the software program, the second schema having a first alias pointing to the first table and a second alias pointing to the second table;
adding entries during uptime to a change table in the first schema characterizing changes to the first table during the data migration, the second schema including a change alias pointing to the change table;
recursively updating the second table to include the entries referred to in the change table using the second application server, the recursively updating comprising;
reading data from the first alias corresponding to the entries referred to in the change table, and writing the data from the first alias to the second alias until a remaining number of the entries is below a pre-defined threshold; and
initiating downtime to migrate remaining entries in the change table to the second table, delete the first table, and rename the second table to have a same name as the first table prior to deletion so that during uptime the second application server connects to the second table and runs the second version of the software program.
2 Assignments
0 Petitions
Accused Products
Abstract
Data is recursively migrated during uptime from a first table to a second table in a first schema in a database while taking into account changes to the first table in a change table. The database has first and second application servers respectively connecting to the database using first and second schemas and running first and second versions of a software program. Downtime can be initiated to migrate the remaining entries in the change table to the second table, delete the first table, and rename the second table to have a same name as the first table prior to deletion so that during uptime the second application server connects to the second table and runs the second version of the software program. Related apparatus, systems, techniques and articles are also described.
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Citations
19 Claims
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1. A computer-implemented method comprising:
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migrating data during uptime from a first table to a second table in a first schema in a database, a first application server connecting to the database using the first schema, a second application server connecting to the database using a second schema, the first application server running a first version of a software program, the second application server running a second version of the software program, the second schema having a first alias pointing to the first table and a second alias pointing to the second table; adding entries during uptime to a change table in the first schema characterizing changes to the first table during the data migration, the second schema including a change alias pointing to the change table; recursively updating the second table to include the entries referred to in the change table using the second application server, the recursively updating comprising;
reading data from the first alias corresponding to the entries referred to in the change table, and writing the data from the first alias to the second alias until a remaining number of the entries is below a pre-defined threshold; andinitiating downtime to migrate remaining entries in the change table to the second table, delete the first table, and rename the second table to have a same name as the first table prior to deletion so that during uptime the second application server connects to the second table and runs the second version of the software program. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A computer-implemented method comprising:
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migrating data during uptime from a first table to a second table in a first schema in a database, a first application server connecting to the database using the first schema, a second application server connecting to the database using a second schema, the first application server running a first version of a software program, the second application server running a second version of the software program, the second schema having a first alias pointing to the first table and a second alias pointing to the second table; adding entries during uptime to a change table in the first schema characterizing changes to the first table during the data migration, the second schema including a change alias pointing to the change table; recursively updating the second table to include the entries referred to in the change table using the second application server, the recursively updating comprising;
reading data from the first alias corresponding to the entries referred to in the change table, and writing the data from the first alias to the second alias until a remaining number of the entries is below a pre-defined threshold, each update comprising sequentially passing through entries in the change table; andinitiating downtime to migrate remaining entries in the change table to the second table, delete the first table, and rename the second table to have a same name as the first table prior to deletion so that during uptime the second application server connects to the second table and runs the second version of the software program.
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19. A non-transitory computer program product storing instructions, which when executed by at least one data processor forming part of a least one computing system, result in operations comprising:
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migrating data during uptime from a first table to a second table in a first schema in a database, a first application server connecting to the database using the first schema, a second application server connecting to the database using a second schema, the first application server running a first version of a software program, the second application server running a second version of the software program, the second schema having a first alias pointing to the first table and a second alias pointing to the second table; adding entries during uptime to a change table in the first schema characterizing changes to the first table during the data migration, the second schema including a change alias pointing to the change table; recursively updating the second table to include the entries referred to in the change table using the second application server, the recursively updating comprising;
reading data from the first alias corresponding to the entries referred to in the change table, and writing the data from the first alias to the second alias until a remaining number of the entries is below a pre-defined threshold; andinitiating downtime to migrate remaining entries in the change table to the second table, delete the first table, and rename the second table to have a same name as the first table prior to deletion so that during uptime the second application server connects to the second table and runs the second version of the software program.
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Specification