A computer-implemented method comprising: receiving a plurality of identifiers of first versions of electronic documents that have been stored in a distributed data storage system and queuing the identifiers in a queue table of a database; obtaining from the queue table, a set of identifiers of the first versions of the electronic documents; invoking , using the set of the identifiers, a query indexing function of a search engine system and receiving a set of matching identifiers of electronic documents, from among the set of identifiers, that match queries that have been registered using the query indexing function; storing the matching identifiers in a last-processed table, wherein the last-processed table tracks, for each of the set of identifiers, a second version of an electronic document that was found to match queries when processed using the query index function, wherein the second version of the electronic document is an earlier version of the electronic document than the first version of the electronic document; obtaining , from the last-processed table, matching identifiers for the second versions of the electronic documents and submitting the matching identifiers to the query indexing function of a search engine system; processing second versions of the electronic documents associated with the matching identifiers, using the query indexing function to determine if the second versions of the electronic documents matches the queries; updating a feed associated with a user account to show messages referring to the first versions of the electronic documents in response to determining that the second versions of the electronic documents do not match the queries. receiving a plurality of identifiers of first versions of electronic documents that have been stored in a distributed data storage system and queuing the identifiers in a queue table of a database; obtaining from the queue table, a set of identifiers of the first versions of the electronic documents; invoking , using the set of the identifiers, a query indexing function of a search engine system and receiving a set of matching identifiers of electronic documents, from among the set of identifiers, that match queries that have been registered using the query indexing function; storing the matching identifiers in a last-processed table, wherein the last-processed table tracks, for each of the set of identifiers, a second version of an electronic document that was found to match queries when processed using the query index function, wherein the second version of the electronic document is an earlier version of the electronic document than the first version of the electronic document; obtaining , from the last-processed table, matching identifiers for the second versions of the electronic documents and submitting the matching identifiers to the query indexing function of a search engine system; processing second versions of the electronic documents associated with the matching identifiers, using the query indexing function to determine if the second versions of the electronic documents matches the queries; updating a feed associated with a user account to show messages referring to the first versions of the electronic documents in response to determining that the second versions of the electronic documents do not match the queries. <EOS>