Classification of annotation semirings over containment of conjunctive queries
We study the problem of query containment of conjunctive queries over annotated databases. Annotations are typically attached to tuples and represent metadata, such as probability, multiplicity, comments, or provenance. It is usually assumed that annotations are drawn from a commutative semiring. Su...
| Main Authors: | , , |
|---|---|
| Format: | Journal article |
| Published: |
Association for Computing Machinery
2017
|
| _version_ | 1826281181450076160 |
|---|---|
| author | Kostylev, E Reutter, J Salamon, A |
| author_facet | Kostylev, E Reutter, J Salamon, A |
| author_sort | Kostylev, E |
| collection | OXFORD |
| description | We study the problem of query containment of conjunctive queries over annotated databases. Annotations are typically attached to tuples and represent metadata, such as probability, multiplicity, comments, or provenance. It is usually assumed that annotations are drawn from a commutative semiring. Such databases pose new challenges in query optimization, since many related fundamental tasks, such as query containment, have to be reconsidered in the presence of propagation of annotations. We axiomatize several classes of semirings for each of which containment of conjunctive queries is equivalent to existence of a particular type of homomorphism. For each of these types, we also specify all semirings for which existence of a corresponding homomorphism is a sufficient (or necessary) condition for the containment. We develop new decision procedures for containment for some semirings which are not in any of these classes. This generalizes and systematizes previous approaches. |
| first_indexed | 2024-03-07T00:24:57Z |
| format | Journal article |
| id | oxford-uuid:7dd33a12-bc37-4fa4-a919-952a6bd8effd |
| institution | University of Oxford |
| last_indexed | 2024-03-07T00:24:57Z |
| publishDate | 2017 |
| publisher | Association for Computing Machinery |
| record_format | dspace |
| spelling | oxford-uuid:7dd33a12-bc37-4fa4-a919-952a6bd8effd2022-03-26T21:06:09ZClassification of annotation semirings over containment of conjunctive queriesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7dd33a12-bc37-4fa4-a919-952a6bd8effdSymplectic Elements at OxfordAssociation for Computing Machinery2017Kostylev, EReutter, JSalamon, AWe study the problem of query containment of conjunctive queries over annotated databases. Annotations are typically attached to tuples and represent metadata, such as probability, multiplicity, comments, or provenance. It is usually assumed that annotations are drawn from a commutative semiring. Such databases pose new challenges in query optimization, since many related fundamental tasks, such as query containment, have to be reconsidered in the presence of propagation of annotations. We axiomatize several classes of semirings for each of which containment of conjunctive queries is equivalent to existence of a particular type of homomorphism. For each of these types, we also specify all semirings for which existence of a corresponding homomorphism is a sufficient (or necessary) condition for the containment. We develop new decision procedures for containment for some semirings which are not in any of these classes. This generalizes and systematizes previous approaches. |
| spellingShingle | Kostylev, E Reutter, J Salamon, A Classification of annotation semirings over containment of conjunctive queries |
| title | Classification of annotation semirings over containment of conjunctive queries |
| title_full | Classification of annotation semirings over containment of conjunctive queries |
| title_fullStr | Classification of annotation semirings over containment of conjunctive queries |
| title_full_unstemmed | Classification of annotation semirings over containment of conjunctive queries |
| title_short | Classification of annotation semirings over containment of conjunctive queries |
| title_sort | classification of annotation semirings over containment of conjunctive queries |
| work_keys_str_mv | AT kostyleve classificationofannotationsemiringsovercontainmentofconjunctivequeries AT reutterj classificationofannotationsemiringsovercontainmentofconjunctivequeries AT salamona classificationofannotationsemiringsovercontainmentofconjunctivequeries |