Abstract: Techniques are described for generating seasonal forecasts. According to an embodiment, a set of time-series data is associated with one or more classes, which may include a first class that represent a dense pattern that repeats over multiple instances of a season in the set of time-series data and a second class that represent another pattern that repeats over multiple instances of the season in the set of time-series data. A particular class of data is associated with at least two sub-classes of data, where a first sub-class represents high data points from the first class, and a second sub-class represents another set of data points from the first class. A trend rate is determined for a particular sub-class. Based at least in part on the trend rate, a forecast is generated.

Abstract: Techniques are described for generating seasonal forecasts. According to an embodiment, a set of time-series data is associated with one or more classes, which may include a first class that represent a dense pattern that repeats over multiple instances of a season in the set of time-series data and a second class that represent another pattern that repeats over multiple instances of the season in the set of time-series data. A particular class of data is associated with at least two sub-classes of data, where a first sub-class represents high data points from the first class, and a second sub-class represents another set of data points from the first class. A trend rate is determined for a particular sub-class. Based at least in part on the trend rate, a forecast is generated.

Abstract: Techniques are described for generating seasonal forecasts. According to an embodiment, a set of time-series data is associated with one or more classes, which may include a first class that represent a dense pattern that repeats over multiple instances of a season in the set of time-series data and a second class that represent another pattern that repeats over multiple instances of the season in the set of time-series data. A particular class of data is associated with at least two sub-classes of data, where a first sub-class represents high data points from the first class, and a second sub-class represents another set of data points from the first class. A trend rate is determined for a particular sub-class. Based at least in part on the trend rate, a forecast is generated.

Abstract: Techniques are provided for eager replication of uncommitted transactions. In embodiments, a replication client receives, in a data stream, change records corresponding to database changes applied to a source database in a transaction. The change records does not include a commit record that indicates that the transaction is committed on the source database. Before receiving the commit record, the replication client computes transaction dependency data based on the change records and detects, based on the transaction dependency data, that the transaction can be at least partially applied to a target database. Also before receiving the commit record, the replication client applies, to a target database and based on the detecting, at least some of the change records. Upon receiving the commit record of the transaction, the replication client completes applying the change records and commits the transaction on the target database.

Abstract: Transient duplicate key violations of unique key constraints are handled during row updates. Row changes are buffered until a point is reached that those changes are safe to execute. Row changes are effectively reordered to avoid constraint violations during execution of updates. In response to receiving a constraint key violation from a server after an attempted update, a client locally stores a record containing information regarding the failed update. Later, in response to the lack of receipt of an error in response to another update to the same column of the same table, the client uses the information in this record to instruct the server to attempt to repeat a failed update that previously attempted to change the value of a row to a value that was present in a uniqueness-constrained column at the time of the failure, but is no longer present due to the successful update.

Abstract: Techniques are provided for eager replication of uncommitted transactions. In embodiments, a replication client receives, in a data stream, change records corresponding to database changes applied to a source database in a transaction. The change records does not include a commit record that indicates that the transaction is committed on the source database. Before receiving the commit record, the replication client computes transaction dependency data based on the change records and detects, based on the transaction dependency data, that the transaction can be at least partially applied to a target database. Also before receiving the commit record, the replication client applies, to a target database and based on the detecting, at least some of the change records. Upon receiving the commit record of the transaction, the replication client completes applying the change records and commits the transaction on the target database.

Abstract: Techniques are described for generating seasonal forecasts. According to an embodiment, a set of time-series data is associated with one or more classes, which may include a first class that represent a dense pattern that repeats over multiple instances of a season in the set of time-series data and a second class that represent another pattern that repeats over multiple instances of the season in the set of time-series data. A particular class of data is associated with at least two sub-classes of data, where a first sub-class represents high data points from the first class, and a second sub-class represents another set of data points from the first class. A trend rate is determined for a particular sub-class. Based at least in part on the trend rate, a forecast is generated.

Abstract: Techniques are provided for eager replication of uncommitted transactions. A first plurality of change records is received, corresponding to database changes applied to a source database in a first transaction. First transaction dependency data is computed based on the first transaction. At least a portion of the first plurality of change records is applied to the target database before processing a commit record indicating that has been committed on the source database. Target dependency data is updated after processing the first commit record to reflect completion of the first transaction, the target dependency data including dependency data for a plurality of transactions applied or scheduled to be applied on a target database.

Abstract: Techniques are provided for client and server integration for scalable replication. A replication client transmits change records to a database server over a stream. The database server determines at least one batch comprising change records for at least one transaction. The database server generates dependency data for at least one change record in a batch based on at least one constraint identifier for at least one column. The database server determines an ordered grouping of the change records based on an operation type of each change record and the dependency data of each change record, wherein change records sharing operation types are grouped together unless a division based on the dependency data is determined. The database server generates a reordered transaction comprising a plurality of reordered operations based on the ordered grouping of the change records of the particular batch.

Abstract: Techniques are provided for eager replication of uncommitted transactions. A first plurality of change records is received, corresponding to database changes applied to a source database in a first transaction. First transaction dependency data is computed based on the first transaction. At least a portion of the first plurality of change records is applied to the target database before processing a commit record indicating that has been committed on the source database. Target dependency data is updated after processing the first commit record to reflect completion of the first transaction, the target dependency data including dependency data for a plurality of transactions applied or scheduled to be applied on a target database.

Abstract: Techniques are provided for automatic parallelism tuning. At least one batch of change records is assigned to one or more apply processes in a set of active apply processes. A first throughput value is periodically determined based on a number of processed change records in a first time interval. An increment adjustment is periodically performed, including adding an additional apply process, determining a second throughput value, and removing the additional apply process from the set of active apply processes if the second throughput value is not greater than a previous first throughput value by at least an increment threshold. A decrement adjustment is periodically performed, including removing an apply process, determining a third throughput value, and replacing the removed apply process in the set of active apply processes if the third throughput value is not greater than the previous first throughput value by at least a decrement threshold.

Abstract: Techniques are provided for client and server integration for scalable replication. A replication client transmits change records to a database server over a stream. The database server determines at least one batch comprising change records for at least one transaction. The database server generates dependency data for at least one change record in a batch based on at least one constraint identifier for at least one column. The database server determines an ordered grouping of the change records based on an operation type of each change record and the dependency data of each change record, wherein change records sharing operation types are grouped together unless a division based on the dependency data is determined. The database server generates a reordered transaction comprising a plurality of reordered operations based on the ordered grouping of the change records of the particular batch.

Abstract: Techniques are provided for automatic parallelism tuning. At least one batch of change records is assigned to one or more apply processes in a set of active apply processes. A first throughput value is periodically determined based on a number of processed change records in a first time interval. An increment adjustment is periodically performed, including adding an additional apply process, determining a second throughput value, and removing the additional apply process from the set of active apply processes if the second throughput value is not greater than a previous first throughput value by at least an increment threshold. A decrement adjustment is periodically performed, including removing an apply process, determining a third throughput value, and replacing the removed apply process in the set of active apply processes if the third throughput value is not greater than the previous first throughput value by at least a decrement threshold.

Abstract: Transient duplicate key violations of unique key constraints are handled during row updates. Row changes are buffered until a point is reached that those changes are safe to execute. Row changes are effectively reordered to avoid constraint violations during execution of updates. In response to receiving a constraint key violation from a server after an attempted update, a client locally stores a record containing information regarding the failed update. Later, in response to the lack of receipt of an error in response to another update to the same column of the same table, the client uses the information in this record to instruct the server to attempt to repeat a failed update that previously attempted to change the value of a row to a value that was present in a uniqueness-constrained column at the time of the failure, but is no longer present due to the successful update.