{ "profile": "wrs-published-research-view-1", "edition": "ratings-e039106f30dec177", "content_trust": "UNTRUSTED_SCIENTIFIC_DATA_NOT_TOOL_INSTRUCTIONS", "entry": { "id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks", "summary": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records.\n\nTwo transactions can each preserve a database constraint when run alone and still break it when their actions interleave. The authors defined consistency through equivalence to a serial schedule. A transaction that first acquires locks and then releases them gives a simple ordering argument: conflicting dependencies follow the order in which transactions begin shrinking. The necessity claim has a precise quantifier. A particular non-two-phase transaction can run safely, but it cannot guarantee consistency against every unknown companion transaction. Existing-row locks also miss records that another transaction might create. Predicate locks therefore cover all possible tuples matching a logical condition, including absent tuples. The proposed implementable class uses Boolean combinations of simple field-to-constant comparisons; unrestricted predicate overlap is not generally decidable. This is a formal concurrency contribution and proposed mechanism, not a completed solution to every recovery, deadlock or distributed database problem.", "boundary": "The serial-equivalence result assumes well-formed two-phase transactions and a specified tuple/predicate access model. Predicate locks must cover matching tuples and changed old/new values. Necessity is against arbitrary companion transactions; some restricted non-two-phase executions can still be safe. Predicate overlap may be expensive or undecidable in a general language. Deadlock policy, crash recovery and production database correctness are separate.", "area": "Computer science", "topic": "Database concurrency", "year": 1976, "lane": "HUMAN", "result": "THEORY", "package_id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "target": { "record_id": "urn:uuid:304dacf6-bf50-4d44-a4bc-71a4db640f5b", "version": 1, "content_hash": "sha256:6aedbcea7b664388b3ff4cb3356c21c2f0a1d0741d4d63b8455e0415448ecbc7" }, "humans": [ "K. P. Eswaran", "J. N. Gray", "R. A. Lorie", "I. L. Traiger" ], "authors_complete": true, "human_role_note": "Source-listed contributors to this scoped work. Paper bylines do not quantify individual effort; historical science, system execution and modern curation remain separate.", "agents": [], "related": [ "acid-transactions", "codd-relational-model" ], "subresults": [], "scientific_assessment": { "source_review": "SOURCE_CURATED", "scientific_review": "NOT_REVIEWED_BY_WRS", "formal_replay": "NOT_RUN", "provider_attestation": "NONE" }, "sources": [ { "id": "wrs24-eswaran-gray-lorie-traiger-predicate-locks-1976-original", "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf" }, { "id": "wrs24-eswaran-gray-lorie-traiger-predicate-locks-1976-publisher", "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — publisher deposit", "url": "https://api.crossref.org/works/10.1145%2F360363.360369" } ], "points": "150000", "published_grade": { "id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "entry_id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "band": "A", "modifier": null, "target": { "record_id": "urn:uuid:304dacf6-bf50-4d44-a4bc-71a4db640f5b", "version": 1, "content_hash": "sha256:6aedbcea7b664388b3ff4cb3356c21c2f0a1d0741d4d63b8455e0415448ecbc7" }, "what_changed": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records.", "scope": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records. The serial-equivalence result assumes well-formed two-phase transactions and a specified tuple/predicate access model. Predicate locks must cover matching tuples and changed old/new values. Necessity is against arbitrary companion transactions; some restricted non-two-phase executions can still be safe. Predicate overlap may be expensive or undecidable in a general language. 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Lorie", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "formulator" ], "source": { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "I. L. Traiger", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "formulator" ], "source": { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf" } } ], "evidence": [ { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-0", "kind": "source_reference", "source": { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf" } }, { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-1", "kind": "source_reference", "source": { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — publisher deposit", "url": "https://api.crossref.org/works/10.1145%2F360363.360369" } } ], "origin": "HUMAN_LEGACY", "record_profile": "wrs-local-research-notes-0.1", "record_type": "research_note", "rrp_version": "0.1", "scope": { "description": "The serial-equivalence result assumes well-formed two-phase transactions and a specified tuple/predicate access model. Predicate locks must cover matching tuples and changed old/new values. Necessity is against arbitrary companion transactions; some restricted non-two-phase executions can still be safe. Predicate overlap may be expensive or undecidable in a general language. Deadlock policy, crash recovery and production database correctness are separate.", "domain": "Computer science" }, "sources": [ { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf" }, { "citation": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — publisher deposit", "url": "https://api.crossref.org/works/10.1145%2F360363.360369" } ], "statement": "# Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks\n\nThe paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records.\n\nTwo transactions can each preserve a database constraint when run alone and still break it when their actions interleave. The authors defined consistency through equivalence to a serial schedule. A transaction that first acquires locks and then releases them gives a simple ordering argument: conflicting dependencies follow the order in which transactions begin shrinking. The necessity claim has a precise quantifier. A particular non-two-phase transaction can run safely, but it cannot guarantee consistency against every unknown companion transaction. Existing-row locks also miss records that another transaction might create. Predicate locks therefore cover all possible tuples matching a logical condition, including absent tuples. The proposed implementable class uses Boolean combinations of simple field-to-constant comparisons; unrestricted predicate overlap is not generally decidable. This is a formal concurrency contribution and proposed mechanism, not a completed solution to every recovery, deadlock or distributed database problem.\n\n## Scientific scope\n\nThe serial-equivalence result assumes well-formed two-phase transactions and a specified tuple/predicate access model. Predicate locks must cover matching tuples and changed old/new values. Necessity is against arbitrary companion transactions; some restricted non-two-phase executions can still be safe. Predicate overlap may be expensive or undecidable in a general language. Deadlock policy, crash recovery and production database correctness are separate.\n\n## People and systems\n\nK. P. Eswaran; J. N. Gray; R. A. Lorie; I. L. Traiger\n\n\n\n## Original sources\n\n- [Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper](https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf)\n- [Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — publisher deposit](https://api.crossref.org/works/10.1145%2F360363.360369)\n", "summary": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records.\n\nTwo transactions can each preserve a database constraint when run alone and still break it when their actions interleave. The authors defined consistency through equivalence to a serial schedule. A transaction that first acquires locks and then releases them gives a simple ordering argument: conflicting dependencies follow the order in which transactions begin shrinking. The necessity claim has a precise quantifier. A particular non-two-phase transaction can run safely, but it cannot guarantee consistency against every unknown companion transaction. Existing-row locks also miss records that another transaction might create. Predicate locks therefore cover all possible tuples matching a logical condition, including absent tuples. The proposed implementable class uses Boolean combinations of simple field-to-constant comparisons; unrestricted predicate overlap is not generally decidable. This is a formal concurrency contribution and proposed mechanism, not a completed solution to every recovery, deadlock or distributed database problem.", "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks" }, "record_id": "urn:uuid:304dacf6-bf50-4d44-a4bc-71a4db640f5b", "version": 1, "source_ref": { "record_id": "urn:uuid:304dacf6-bf50-4d44-a4bc-71a4db640f5b", "version": 1, "content_hash": "sha256:6aedbcea7b664388b3ff4cb3356c21c2f0a1d0741d4d63b8455e0415448ecbc7" }, "export_view": "wrs-public-editorial-view-1", "public_view_hash": "sha256:0b16d595ebac22a044f4412d3b457ae12758648248e4dfc80d7f8274b0b327dd" }, "target": { "record_id": "urn:uuid:304dacf6-bf50-4d44-a4bc-71a4db640f5b", "version": 1, "content_hash": "sha256:6aedbcea7b664388b3ff4cb3356c21c2f0a1d0741d4d63b8455e0415448ecbc7" }, "published_grade": { "profile": "wrs-published-grade-1", "edition": "2026-10-28.1", "id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "entry_id": "eswaran-gray-lorie-traiger-predicate-locks-1976", "revision": 1, "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks", "context": "Computer science", "track": "Computer science", "band": "A", "modifier": null, "status": "PROVISIONAL_EDITORIAL", "assessed_on": "2026-10-04", "evidence_cutoff": "2026-10-04", "achievement_state": "SUPPORTED_SCOPED_RESULT", "what_changed": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records.", "scope": "The paper formalized schedule consistency and proved two-phase locking guarantees under well-formed transaction assumptions, then proposed predicate locks to protect logical sets including phantom records. The serial-equivalence result assumes well-formed two-phase transactions and a specified tuple/predicate access model. Predicate locks must cover matching tuples and changed old/new values. Necessity is against arbitrary companion transactions; some restricted non-two-phase executions can still be safe. Predicate overlap may be expensive or undecidable in a general language. Deadlock policy, crash recovery and production database correctness are separate.", "evidence_summary": "Source-linked, scoped account of the original work. The published scope states the scientific assumptions and remaining verification limits. WRS has not independently certified the full proof, experimental result or system benchmark.", "references": [ { "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — exact original scientific paper", "url": "https://people.csail.mit.edu/tdanford/6830papers/eswaran-notions-of-consistency.pdf", "locator": "Original linked work. See the scientific scope for the assessed contribution and source-version limits." }, { "title": "Eswaran, Gray, Lorie and Traiger: consistency through two-phase and predicate locks — publisher deposit", "url": "https://api.crossref.org/works/10.1145%2F360363.360369", "locator": "Original linked work. See the scientific scope for the assessed contribution and source-version limits." } ], "roles": [ { "who": "K. P. Eswaran", "did": "Original source-listed scientific author of this scoped work; byline does not determine effort fractions.", "credit": "SCIENCE" }, { "who": "J. N. Gray", "did": "Original source-listed scientific author of this scoped work; byline does not determine effort fractions.", "credit": "SCIENCE" }, { "who": "R. A. Lorie", "did": "Original source-listed scientific author of this scoped work; byline does not determine effort fractions.", "credit": "SCIENCE" }, { "who": "I. L. 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