Coupling table specification system, coupling table search device, method, and program

A coupling table specification method performed by a computer and comprising:

• receiving a target column;
• generating a search plan defining a use order of each of indexes based on a number of records in external tables to be joined with a target column, the number calculated by using each of the indexes;
• and
• searching, in the use order defined in the search plan, one or more tables to be coupled with the target column in the external tables, wherein
• each of the indexes defines records in the external tables, the records being selected based on similarity functions calculating a score between the records, and
• the coupling table specification method further comprises:
• extracting from each external table, a coupling column candidate that is a column including a record serving as a key of coupling to another table among the external tables included in an external table group;
• and
• generating a coupling index of the extracted coupling column candidate for each similarity function, and storing the generated coupling index in a coupling index storage.

A non-transitory computer readable information recording medium storing a coupling table search program executable by a processor to perform a method comprising:

• receiving a target column;
• generating a search plan defining a use order of each of indexes based on a number of records in external tables to be joined with a target column, the number calculated by using each of the indexes;
• and
• searching, in the use order defined in the search plan, one or more tables to be coupled with the target column in the external tables, wherein
• each of the indexes defines records in the external tables, the records being selected based on similarity functions calculating a score between the records, and
• the method further comprises:
• extracting from each external table, a coupling column candidate that is a column including a record serving as a key of coupling to another table among the external tables included in an external table group;
• and
• generating a coupling index of the extracted coupling column candidate for each similarity function, and storing the generated coupling index in a coupling index storage.