Systems and/or methods for migrating live database schemas to support zero downtime deployments with zero data losses

A non-transitory computer readable storage medium storing instructions that, when executed by at least one processor of a database server configured to receive and respond to requests from external client devices using a database hosted thereon, cause the database server to migrate data in the database to a target database schema from tables structured according to a source database schema by performing operations comprising:

• in a setup stage, while allowing data modifications to be performed on the tables in the database structured according to the source database schema:
• creating, on the database server, a migration reference table and a migration change log table in response to an indication that data in the database is to be migrated;
• automatically populating the migration reference table with instructions performable to implement changes to accommodate the migration;
• automatically generating a custom migration procedure, performable within the database server, to process the instructions in the migration reference table to perform the migration;
• and
• automatically creating triggers of at least at least three different trigger types, the triggers structured to (a) during a backup stage, record in the migration change log table, information about data-related actions performed on tables in the database structured according to the source database schema, and (b) during a migration stage, processing further data-related actions performed on tables in the database structured according to the source database schema by attempting to modify new tables structured according to the target database schema, wherein anticipated exceptions encountered during the processing are handled by writing entries to the migration change log table, wherein the triggers are automatically performable within the database server once activated;
• in the backup stage:
• activating the created triggers to enable the recording of (a);
• and
• running the generated custom migration procedure to conform a restored version of the data in the tables structured according to the source database schema to the target database schema, while the created triggers are activated and while also allowing data modifications to be performed on the tables in the database structured according to the source database schema;
• in the migration stage:
• replicating, using the generated custom migration procedures, in the tables structured according to the target database schema, data modifications made to the tables in the database structured according to the source database schema during the backup stage by processing the information about the data-related actions recorded in the migration change log table, while continuing to have the created triggers active to perform the replaying of (b);
• and
• following the migration stage, receiving and responding to new incoming requests in connection with the tables structured according to the target database schema.

A database server, comprising:

• a database backed by a non-transitory computer readable storage medium;
• at least one processor configured to receive and respond to requests from external client devices using a database hosted thereon,
• the at least one processor being further configured to cause the database server to migrate data in the database to a target database schema from tables structured according to a source database schema by performing operations comprising:
• in a setup stage, while allowing data modifications to be performed on the tables in the database structured according to the source database schema:
• creating, on the database server, a migration reference table and a migration change log table in response to an indication that data in the database is to be migrated;
• automatically populating the migration reference table with instructions performable to implement changes to accommodate the migration;
• automatically generating a custom migration procedure, performable within the database server, to process the instructions in the migration reference table to perform the migration;
• and
• automatically creating triggers of at least at least three different trigger types, the triggers structured to (a) during a backup stage, record in the migration change log table, information about data-related actions performed on tables in the database structured according to the source database schema, and (b) during a migration stage, processing further data-related actions performed on tables in the database structured according to the source database schema by attempting to modify new tables structured according to the target database schema, wherein anticipated exceptions encountered during the processing are handled by writing entries to the migration change log table, wherein the triggers are automatically performable within the database server once activated;
• in the backup stage:
• activating the created triggers to enable the recording of (a);
• and
• running the generated custom migration procedure to conform a restored version of the data in the tables structured according to the source database schema to the target database schema, while the created triggers are activated and while also allowing data modifications to be performed on the tables in the database structured according to the source database schema;
• in the migration stage:
• replicating, using the generated custom migration procedures, in the tables structured according to the target database schema, data modifications made to the tables in the database structured according to the source database schema during the backup stage by processing the information about the data-related actions recorded in the migration change log table, while continuing to have the created triggers active to perform the replaying of (b);
• and
• following the migration stage, receiving and responding to new incoming requests in connection with the tables structured according to the target database schema.