Abstract: In some examples, a system may use content classes to manage indexing of object data. A content class may include a set of one or more content properties. Each content property may include a name, an expression for extracting data, and an expression type. When object data is received, such as for indexing, the expression type of each content property may be compared with the data type of the received data. Based at least in part on determining that the expression type matches the data type, the system may extract a data value from the received data in accordance with the expression. The system may save the extracted data value to a data structure in association with the name of the content property, and may subsequently use the data value and the name of the content property when creating an index for the object data.

Abstract: In some examples, a plurality of nodes may each host a respective logical database (LDB) that includes database data that references external resources stored in a storage system. Further, each node may maintain, for each external resource referenced by the respective LDB on that node, a reference count of a number of references in the respective LDB to each external resource and a timestamp associated with the reference count. In response to addition of a reference to a particular external resource in a particular LDB, a node that hosts the particular LDB may be programmed to increment the reference count and update the timestamp for the particular external resource. Similarly, in response to removal of the reference to the particular external resource in the particular LDB, the node hosting the particular LDB is programmed to decrement the reference count and update the timestamp for the particular external resource.

Abstract: In some examples, a system may use content classes to manage indexing of object data. A content class may include a set of one or more content properties. Each content property may include a name, an expression for extracting data, and an expression type. When object data is received, such as for indexing, the expression type of each content property may be compared with the data type of the received data. Based at least in part on determining that the expression type matches the data type, the system may extract a data value from the received data in accordance with the expression. The system may save the extracted data value to a data structure in association with the name of the content property, and may subsequently use the data value and the name of the content property when creating an index for the object data.

Abstract: In some examples, a plurality of nodes may each host a respective logical database (LDB) that includes database data that references external resources stored in a storage system. Further, each node may maintain, for each external resource referenced by the respective LDB on that node, a reference count of a number of references in the respective LDB to each external resource and a timestamp associated with the reference count. In response to addition of a reference to a particular external resource in a particular LDB, a node that hosts the particular LDB may be programmed to increment the reference count and update the timestamp for the particular external resource. Similarly, in response to removal of the reference to the particular external resource in the particular LDB, the node hosting the particular LDB is programmed to decrement the reference count and update the timestamp for the particular external resource.