Abstract: In one embodiment, a method includes accessing a place-entities graph comprising a plurality of place-entity nodes, in which each place-entity node representing a place-entity corresponding to a particular geographic location, and identifying a place-entity cluster within the place-entities graph. The place-entity cluster comprises a plurality of place-entity nodes corresponding to a plurality of place-entities corresponding to the same geographic location. The method includes accessing embeddings representing the plurality of place-entities corresponding to the place-entity cluster. Each embedding is a point in a d-dimensional embedding space. The method includes calculating, using a machine-learning model, a cluster-quality score of the place-entity cluster based on the embeddings. The cluster-quality score represents a probability that the place-entities correspond to a valid geographic location.

Abstract: In one embodiment, a method includes receiving, from a client system associated with a user of an online social network, data indicating that the user is located at a first geographic location at a first time; accessing a first embedding representing a first place-entity corresponding to the first geographic location; accessing multiple second embeddings representing multiple respective second place-entities each corresponding to a second geographic location; calculating, a similarity metric between the embedding representing the first place-entity and each of the embeddings representing the second place-entities; ranking each of the second place-entities based on their calculated similarity metrics; and sending, to the client system, information associated with one or more second geographic locations corresponding to one or more second place-entities having a ranking greater than a threshold ranking.

Abstract: In one embodiment, a method includes receiving, from a client system, a search query, identifying a plurality of place-entity nodes matching the search query, determining that one or more of the identified place-entity nodes are low-quality place-entity nodes based on the place names of the place-entity nodes having anomalous language characteristics, filtering the plurality of identified place-entity nodes to exclude the determined low-quality place-entity nodes, and generating one or more search results corresponding to the plurality of filtered place-entity nodes.

Abstract: In one embodiment, a method includes receiving from a client system a search query, identifying a first place-entity based on the search query, accessing a place-entities graph comprising a plurality of place-entity nodes, each place-entity node representing a particular place-entity associated with a particular geographic location, wherein the first place-entity is represented by a first place-entity node, accessing a redirection graph comprising the plurality of place-entity nodes and a plurality of place-entity clusters, each place-entity node in a place-entity cluster having a redirection edge connecting the place-entity node to a canonical place-entity node of the respective place-entity cluster, and sending a response to the search query, wherein if the first place-entity node is connected to a canonical place-entity node by a redirection edge within the redirection graph, the response comprises a reference to the canonical place-entity node, else the response comprises a reference to the first place-en

Abstract: In one embodiment, a method includes identifying one or more place-entity nodes in a heterogeneous graph, wherein the heterogenous graph comprises place-entity nodes, user nodes, and n-gram nodes, and wherein each place-entity node corresponds to a place-entity associated with a particular geographic location, assigning, for each identified place-entity node, an initial quality-score for the place-entity node, and calculating, for each identified place-entity node, a final quality-score for the identified place-entity node, wherein each final quality-score is calculated by iteratively propagating the initial quality-scores corresponding to the identified place-entity nodes, respectively, through the place-entity nodes, n-gram nodes, and user nodes of the heterogeneous graph until the quality-scores associated with the place-entity nodes, n-gram nodes, and user nodes reach convergence.

Abstract: Detection of abnormalities in HDBD is performed by processing it to obtain a dictionary from a training data. This is done by computing a low rank randomized LU decomposition which enables constant online updating of the training data and thus gets constant updating of the normal profile in the background.

Abstract: In one embodiment, a method includes receiving from a client system of a user, background signal-information identifying one or more first wireless signals within wireless communication range of the client system; accessing a place-entity database, wherein the place-entity database comprises information indicating that a first place-entity corresponds to one or more second wireless signals; determining that the client system is located at a geographic location associated with the first place-entity based on determining that the one or more first wireless signals match the one or more second wireless signals and further based on the information indicating that the first place-entity corresponds to the one or more second wireless signals; and sending, to the client system, information associated with the first place-entity automatically without a query from the user of the client system, wherein the query is related to the first place-entity.

Abstract: In one embodiment, a method includes receiving from a client system a search query, identifying a first place-entity based on the search query, accessing a place-entities graph comprising a plurality of place-entity nodes, each place-entity node representing a particular place-entity associated with a particular geographic location, wherein the first place-entity is represented by a first place-entity node, accessing a redirection graph comprising the plurality of place-entity nodes and a plurality of place-entity clusters, each place-entity node in a place-entity cluster having a redirection edge connecting the place-entity node to a canonical place-entity node of the respective place-entity cluster, and sending a response to the search query, wherein if the first place-entity node is connected to a canonical place-entity node by a redirection edge within the redirection graph, the response comprises a reference to the canonical place-entity node, else the response comprises a reference to the first place-en

Abstract: In one embodiment, a method includes receiving, from a client system associated with a user of an online social network, data indicating that the user is located at a first geographic location at a first time; accessing a first embedding representing a first place-entity corresponding to the first geographic location; accessing multiple second embeddings representing multiple respective second place-entities each corresponding to a second geographic location; calculating, a similarity metric between the embedding representing the first place-entity and each of the embeddings representing the second place-entities; ranking each of the second place-entities based on their calculated similarity metrics; and sending, to the client system, information associated with one or more second geographic locations corresponding to one or more second place-entities having a ranking greater than a threshold ranking.

Abstract: In one embodiment, a method includes receiving from a client system of a user, background signal-information identifying one or more first wireless signals within wireless communication range of the client system; accessing a place-entity database, wherein the place-entity database comprises information indicating that a first place-entity corresponds to one or more second wireless signals; determining that the client system is located at a geographic location associated with the first place-entity based on determining that the one or more first wireless signals match the one or more second wireless signals and further based on the information indicating that the first place-entity corresponds to the one or more second wireless signals; and sending, to the client system, information associated with the first place-entity automatically without a query from the user of the client system, wherein the query is related to the first place-entity.

Abstract: In one embodiment, a method includes accessing a place-entities graph comprising place-entity nodes, each place-entity node representing a place-entity corresponding to a particular geographic location; identifying a place-entity cluster within the place-entities graph, wherein the place-entity cluster includes place-entity nodes corresponding to respective place-entities each corresponding to the same geographic location; accessing embeddings representing the respective place-entities corresponding to the place-entity cluster; calculating, using a machine-learning model, a cluster-quality score of the place-entity cluster based on the embeddings representing the place-entities corresponding to the place-entity cluster, wherein the cluster-quality score represents a probability that the place-entities corresponding to the place-entity cluster correspond to a valid geographic location; and identifying the place-entities corresponding to the place-entity cluster as corresponding to an invalid geographic locatio

Abstract: In one embodiment, an online social network accesses a place-entities graph that includes a plurality of place-entity nodes, each place-entity node representing a particular place-entity associated with a particular geographic location. From one of a plurality of search clients associated with the online social network, a threshold duplication value and a threshold redirect value is received. The online social network identifies place-entity clusters of place-entity nodes within the place-entities graph. In each place-entity cluster, the place-entity nodes have duplication values with respect to a canonical place-entity node in the cluster that are above the threshold duplication value. The online social network generates a redirection graph for the one search client.

Abstract: In one embodiment, a method includes receiving, from a first software application of a client system associated with a user of an online social network, background signal-information identifying one or more first wireless signals; storing the signal-information and a client identifier for the client system in a signal-information database; receiving, from a second software application of the client system via a places-API of the online social network, a places-API call indicating that the client system is located at a geographic location corresponding to a first place-entity; recording the places-API call in an API-call log, wherein the API-call log records the first place-entity and the client identifier; determining a correlation between the signal-information and the first place-entity; and updating a place-entity database to indicate that the first place-entity corresponds to the one or more first wireless signals identified by the signal-information.

Abstract: In one embodiment, a method includes identifying one or more place-entity nodes in a heterogeneous graph, wherein the heterogenous graph comprises place-entity nodes, user nodes, and n-gram nodes, and wherein each place-entity node corresponds to a place-entity associated with a particular geographic location, assigning, for each identified place-entity node, an initial quality-score for the place-entity node, and calculating, for each identified place-entity node, a final quality-score for the identified place-entity node, wherein each final quality-score is calculated by iteratively propagating the initial quality-scores corresponding to the identified place-entity nodes, respectively, through the place-entity nodes, n-gram nodes, and user nodes of the heterogeneous graph until the quality-scores associated with the place-entity nodes, n-gram nodes, and user nodes reach convergence.

Abstract: In one embodiment, an online social network accesses a social graph that includes a number of place-entity nodes each corresponding to a place-entity, and a number of user nodes each corresponding to a user. A heterogeneous graph is generated based on the place-entity nodes, user nodes, and n-gram nodes, each n-gram node corresponding to an n-gram in the name of at least one place-entity. Each n-gram node is connected to corresponding place-entity nodes containing the n-gram, and user nodes with a social networking interaction with the corresponding place-entity nodes. Each place-entity node is assigned an initial quality-score. The quality-scores are propagated through the redirection graph based on the connections between the place-entity nodes, the n-gram nodes, and the user nodes. A final quality-score is assigned to each place-entity node when the propagation of the quality-scores through the redirection graph reaches convergence.

Abstract: A method for live database schema tree change, comprising: (a) providing a computerized database comprising: a parent database table and a child database table having a column configured to reference the parent database table; and (b) while the computerized database is live, operating a database management system (DBMS) in control of the computerized database, to: create an intermediate database table having a column configured to reference the parent database table; in the child database table: create a column configured to reference the intermediate database table, insert an identifier of the intermediate database table into all fields of the column configured to reference the intermediate database table, and overwrite all fields of the column configured to reference the parent database table with data from the fields of the column configured to reference the intermediate database table.

Abstract: In one embodiment, an online social network accesses a place-entities graph that includes a plurality of place-entity nodes, each place-entity node representing a particular place-entity associated with a particular geographic location. From one of a plurality of search clients associated with the online social network, a threshold duplication value and a threshold redirect value is received. The online social network identifies place-entity clusters of place-entity nodes within the place-entities graph. In each place-entity cluster, the place-entity nodes have duplication values with respect to a canonical place-entity node in the cluster that are above the threshold duplication value. The online social network generates a redirection graph for the one search client.

Abstract: In one embodiment, an online social network accesses a social graph that includes a number of place-entity nodes each corresponding to a place-entity, and a number of user nodes each corresponding to a user. A heterogeneous graph is generated based on the place-entity nodes, user nodes, and n-gram nodes, each n-gram node corresponding to an n-gram in the name of at least one place-entity. Each n-gram node is connected to corresponding place-entity nodes containing the n-gram, and user nodes with a social networking interaction with the corresponding place-entity nodes. Each place-entity node is assigned an initial quality-score. The quality-scores are propagated through the redirection graph based on the connections between the place-entity nodes, the n-gram nodes, and the user nodes. A final quality-score is assigned to each place-entity node when the propagation of the quality-scores through the redirection graph reaches convergence.

Abstract: A method for live database schema tree change, comprising: (a) providing a computerized database comprising: a parent database table and a child database table having a column configured to reference the parent database table; and (b) while the computerized database is live, operating a database management system (DBMS) in control of the computerized database, to: create an intermediate database table having a column configured to reference the parent database table; in the child database table: create a column configured to reference the intermediate database table, insert an identifier of the intermediate database table into all fields of the column configured to reference the intermediate database table, and overwrite all fields of the column configured to reference the parent database table with data from the fields of the column configured to reference the intermediate database table.

Abstract: To transmit data, a set of at least 2m n×n matrices that represent an extension of a fixed-point-free group is provided. To each of 2m of the matrices is allocated one of the binary numbers from 0 to 2m?1. The data are mapped into the matrices according to the allocation. The mapped matrices are transmitted, preferably using n antennas, one antenna per row of each matrix.