Abstract: A log-structured data store implementing data backup may implement variable data replication. Write requests may be received at different storage nodes maintaining respective replicas of a portion of a log for data maintained in the log-structured data store. Log records indicating the write requests may be stored in the respective replicas of the log portions at the different storage nodes. The log records may be sent to a backup data store to be durability persisted as part of an archived version of the log. At some of the storage nodes, in response to determining that the log records have been durably persisted in the backup data store, storage space for the log records may be reclaimed. In other remaining storage nodes, the log records may be retained and made accessible for servicing read requests.

Abstract: A database system may include a database service and a separate distributed storage service. The database service (or a database engine head node thereof) may be responsible for query parsing, optimization, and execution, transactionality, and consistency, while the storage service may be responsible for generating data pages from redo log records and for durability of those data pages. For example, in response to a write request directed to a particular data page, the database engine head node may generate a redo log record and send it, but not the data page, to a storage service node. The storage service node may store the redo log record and return a write acknowledgement to the database service prior to applying the redo log record. The server node may apply the redo log record and other redo log records to a previously stored version of the data page to create a current version.

Abstract: A database system may include a database service and a separate distributed storage service. The database service (or a database engine head node thereof) may be responsible for query parsing, optimization, and execution, transactionality, and consistency, while the storage service may be responsible for generating data pages from redo log records and for durability of those data pages. For example, in response to a write request directed to a particular data page, the database engine head node may generate a redo log record and send it, but not the data page, to a storage service node. The storage service node may store the redo log record and return a write acknowledgement to the database service prior to applying the redo log record. The server node may apply the redo log record and other redo log records to a previously stored version of the data page to create a current version.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: Example implementations relate to point of sale cables. For example, a system may comprise a point of sale terminal coupled to a splitter via a registered jack (RJ) cable to provide electrical power to the splitter, a receipt printer coupled to receive electrical power from the splitter at a DIN connector input, and a cash drawer to receive electrical power from the splitter via an RJ connector input.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: Example implementations relate to point of sale cables. For example, a system may comprise a point of sale terminal coupled to a splitter via a registered jack (RJ) cable to provide electrical power to the splitter, a receipt printer coupled to receive electrical power from the splitter at a DIN connector input; and a cash drawer to receive electrical power from the splitter via an RJ connector input.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: A database system may include a database service and a separate distributed storage service. The database service (or a database engine head node thereof) may be responsible for query parsing, optimization, and execution, transactionality, and consistency, while the storage service may be responsible for generating data pages from redo log records and for durability of those data pages. For example, in response to a write request directed to a particular data page, the database engine head node may generate a redo log record and send it, but not the data page, to a storage service node. The storage service node may store the redo log record and return a write acknowledgement to the database service prior to applying the redo log record. The server node may apply the redo log record and other redo log records to a previously stored version of the data page to create a current version.

Abstract: A data store may implement variable data replication and quorum-based durability schemes. Write requests may be maintained in complete views of the data or incomplete views of the data at storage nodes in a quorum set in the data store. Write requests may be received at different storage nodes sufficient to establish a write quorum, and stored in the replicas of the data at the storage nodes where they are received. Storage nodes maintaining incomplete views of the data may determine that each of the storage nodes maintaining a complete view of the data in the quorum set stores certain write requests, and in response, may reclaim storage space for those write requests included in the incomplete views of the data in order to store other data at the storage node.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: A database system may include a database service and a separate distributed storage service. The database service (or a database engine head node thereof) may be responsible for query parsing, optimization, and execution, transactionality, and consistency, while the storage service may be responsible for generating data pages from redo log records and for durability of those data pages. For example, in response to a write request directed to a particular data page, the database engine head node may generate a redo log record and send it, but not the data page, to a storage service node. The storage service node may store the redo log record and return a write acknowledgement to the database service prior to applying the redo log record. The server node may apply the redo log record and other redo log records to a previously stored version of the data page to create a current version.

Abstract: Some embodiments of the invention are directed to enabling a user to modify the manner in which one or more settings specified by a predefined template for a particular sound source are applied, so as to provide the user with greater control over the settings which are applied to a track than conventional tools afford. Some embodiments are directed to automatically applying one or more settings for a track based at least in part upon an analysis of the spectral and/or dynamic content of the track, such as by automatically performing sound equalization by applying one or more digital filters to a track, defining the frequency range(s) in which one or more filter(s) are applied, applying dynamic range compression, defining the manner in which compression is applied in multiple sub-bands of the audible spectrum, and/or applying one or more other settings. Such settings may be designed to achieve any of numerous (e.g.

Abstract: Hybrid quorum policies may be implemented for access requests to state maintained in a distributed system. An update to state maintained in a distributed system may be sent to multiple nodes in the distributed system maintain the state in order to satisfy a hybrid quorum policy for updating the state in the distributed system. The hybrid quorum policy may include individual quorum policies for multiple quorum sets including nodes of the distributed system. Acknowledgments received from nodes in the distributed system indicating that the update is performed may be evaluated according to the individual quorum policies to determine whether the hybrid quorum policy is satisfied. If the hybrid quorum policy is satisfied, then the update to the state may be considered durable.

Abstract: A log-structured data store may implement optimized log storage for asynchronous log updates. In some embodiments, log records may be received indicating updates to data stored for a storage client and indicating positions in a log record sequence. The log records themselves may not be guaranteed to be received according to the log record sequence. Received log records may be stored in a hot log portion of a block-based storage device according to an order in which they are received. Log records in the hot log portion may then be identified to be moved to a cold log portion of the block-based storage device in order to complete a next portion of the log record sequence. Log records may be modified, such as compressed, or coalesced, before being stored together in a data block of the cold log portion according to the log record sequence.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: A log-structured data store may implement efficient garbage collection. Log records may be maintained in data blocks according to a log record sequence. Based, at least in part, on a log reclamation point, the log records may be evaluated to identify data blocks to reclaim that have log records in the log sequence prior to the log reclamation point. New versions of data pages updated by log records in the identified data blocks may be generated and stored in base page storage for the log structured data store. The identified data blocks may then be reclaimed for storing new data.

Abstract: Some embodiments of the invention are directed to enabling a user to easily identify the frequency range(s) at which sound masking occurs, and addressing the masking, if desired. In this respect, the extent to which a first stem is masked by one or more second stems in a frequency range may depend not only on the absolute value of the energy of the second stem(s) in the frequency range, but also on the relative energy of the first stem with respect to the second stem(s) in the frequency range. Accordingly, some embodiments are directed to modeling sound masking as a function of the energy of the stem being masked and of the relative energy of the masked stem with respect to the masking stem(s) in the frequency range, such as by modeling sound masking as loudness loss, a value indicative of the reduction in loudness of a stem of interest caused by the presence of one or more other stems in a frequency range.

Abstract: A database management system may utilize a log-structured storage system instead of a conventional storage system. The log-structured storage system may store a baseline of an object and a series of log entries describing changes to the object. At various positions in the log, a combined record may be written to contain a description of a change to the object and a copy of the corresponding version of the object. Combined records may be used to employ alternative strategies for constructing or transmitting a version of an object. Embodiments may employ these alternative strategies for replication and data caches.