Consistency management using query restrictions in journal-based storage systems

A method, comprising:

• determining, at a client-side component of a multi-data-store storage system, a query restriction descriptor indicating one or more attributes of a data object, wherein read-write conflicts associated with the one or more attributes of the data object indicated by the query restriction descriptor are to be detected by a journal manager of the multi-data-store storage system with respect to proposed transactions, wherein the client-side component is implemented at a first set of one or more computing devices, and wherein the journal manager is implemented at a second set of one or more computing devices;
• generating, at the client-side component, a read set descriptor of a first proposed transaction, wherein a read set of the first proposed transaction comprises results of a first query, wherein the first query includes a predicate comprising an attribute of the one or more attributes of the data object indicated by the query restriction descriptor, and wherein the read set descriptor of the first proposed transaction includes a result of a first transformation operation on at least the attribute of the predicate of the first query;
• transmitting the first proposed transaction from the client-side component to the journal manager;
• and
• approving, at the journal manager, the first proposed transaction for commit, based at least in part on a result of a read-write conflict detection between the read set descriptor of the proposed transaction and respective write set descriptors of one or more previously-committed transactions, wherein the read-write conflict detection is based on a determination of whether the result of the first transformation operation on the predicate of the first query matches a result of a second transformation operation applied to respective predicates associated with the one or more previously-committed transactions, wherein a write set descriptor of a previously-committed transaction corresponds to a write operation of the previously-committed transaction and wherein the write set descriptor of the previously-committed transaction is stored in a commit record in a journal of the multi-data-store storage system, and wherein the write set descriptor includes a result of the second transformation operation on a predicate of a second query directed to the one or more attributes of the data object indicated by the query restriction descriptor, wherein a result of the second query is affected by the write operation.

A non-transitory computer-accessible storage medium storing program instructions that when executed on one or more processors implement a client-side component of a multi-data-store storage system, wherein the client-side component is configured to:

• determine a query restriction descriptor indicating one or more attributes of a data object, wherein queries directed to the one or more attributes of the data object indicated by the query restriction descriptor are to be represented within read set descriptors of proposed transactions directed to a journal manager of the multi-data-store storage system;
• generate a first read set descriptor of a first proposed transaction, wherein a read set of the first proposed transaction comprises results of a first query, wherein the first query includes a predicate comprising an attribute of the one or more attributes of the data object indicated by the query restriction descriptor, and wherein the first read set descriptor of the first proposed transaction includes a result of a first transformation function applied to at least the attribute of the predicate of the first query;
• transmit the proposed transaction to the journal manager of the multi-data-store storage system, wherein the journal manager is responsible for approving the first proposed transaction for commit based at least in part on a result of a check for read-write conflicts between the read set descriptor of the proposed transaction and respective write set descriptors of one or more previously-committed transactions, wherein the check for read-write conflicts is based on a determination of whether the result of the first transformation function applied to the predicate of the first query matches a result of a second transformation function applied to respective predicates associated with the one or more previously-committed transactions, wherein the respective write set descriptors of the one or more previously-committed transactions correspond to write operations of the one or more previously-committed transactions and are stored in respective commit records in a journal of the multi-data-store database.