Apparatus and method for indexing electronic content

A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method of operating a content index, the method comprising:

• indexing multiple sets of electronic content in a computer system memory, wherein each set of electronic content is indexed by storing in the index a corresponding entry comprising:
• metadata relating to the set of electronic content;
• and
• one or more integer tokens, each integer token representing an attribute of a target audience of the set of electronic content and a corresponding value of the attribute;
• receiving a request for content to be served to a target user, the target user having a set of attributes and corresponding values;
• searching the index for entries comprising integer tokens representing a subset of the set of attributes and corresponding values of the target user;
• and
• in response to the request for content, communicating identities of one or more sets of electronic content having attributes and corresponding values matching a subset of the set of attributes and corresponding values of the target user.

A non-transitory computer-readable medium containing a data structure for indexing electronic content items for serving in response to content requests items, the data structure comprising:

• multiple independent slices, each slice comprising:
• metadata for:
• identifying the slice;
• and
• controlling access to the slice;
• and
• multiple entries, each entry corresponding to an item of electronic content and comprising:
• metadata relating to the corresponding item;
• and
• multiple integer tokens, each integer token representing an attribute of a target audience of the item of electronic content and a value of that attribute.

A system for operating a content index, the system comprising:

• a memory comprising:
• an index of electronic content, wherein each entry in the index:
• corresponds to a set of electronic content;
• and
• comprises a set of integer tokens representing attributes of a target audience of the set of electronic content and corresponding values of the attributes;
• and
• a queue for storing updates to the index;
• wherein the index comprises multiple independent slices, each slice comprising multiple index entries;
• and
• reader logic for searching the index, in response to a request for content, for entries having target audiences matching a target user to whom the requested content is to be presented.