Sap Se

Sap Ag

Wolfgang Stephan

Thomas Peh

Holger Schwedes

Till Merker

Andrew Ross

Frank Renkes

Manuel Mayr

Juchang Lee

Christian Bensberg

Lars Fricke

Taehyung Lee

Chuho Chang

Felix Knittel

Chang Gyoo Park

Guenter Radestock

Michael Muehle

Frederik Transier

Jaeyun Noh

Andreas Tonder

Klaus Otto Mueller

Oliver Horn

Oliver M Steinau

Nico Bohnsack

Arnaud Lacurie

Christian M Bartholomae

Joerg Fellmann

Dennis Felsing

Hyungyu Shin

Seongyun Ko

Mortiz Thomas

Franz-X Faerber

A system and method is provided for implementing a table scan predicate with integrated semi-join filter. The method includes receiving a query including a request to join first data from a first dimension table and second data from a second dimension table with fact data from a fact table. The method includes applying a first dynamic predicate to the first data by collecting the first data based on a first expression of the query and filtering the first column. The method also includes applying a second dynamic predicate to the second data by collecting the second data based on a second expression of the query and filtering the second column. The method also includes executing the query by at least scanning the fact table based on the query, the first filtered column, and the second filtered column.

Table scan predicate with integrated semi-join filter

In some implementations, there is provided a method including receiving a query request including a join, wherein the join includes a range between a first predicate of the join and a second predicate of the join; generating a query plan including an index join operator; executing the query plan including the index join operator including getting, from the sorted dictionary, the first value identifier, the second value identifier, and the one or more intervening value identifiers between the first value identifier and the second value identifier and executing the index join operator using the first value identifier, the second value identifier, and the one or more intervening value identifiers to obtain a result set.

Index join query optimization

Systems and methods are provided for text searching using partial score expressions. A method may include receiving a query to search for a search term in at least a first column of a first table and a second column of a second table, scanning the first column and the second column for at least a portion of the search term, generating a first partial score table, generating a second partial score table, determining a combined score for each row in the first column and/or the second column containing at least the portion of the search term based at least on a join of the first partial score table and the second partial score table, and providing, in response to the query and based at least on the combined score, a row of the first column and/or the second column including at least the portion of the search term.

Text searching using partial score expressions

A table scan predicate with integrated semi-join filter is provided. A method includes receiving a query including: a request to join first data from a first table and second data from a second table, a first predicate for use in a table scan of the second table, and a second predicate including an expression associated with the first data from the first table and a reference to a column associated with the second data from the second table. The method may include transforming the second predicate into a dynamic predicate for execution of the query. the method may include applying the dynamic predicate to at least the first data. The method may include executing the query by at least scanning the second table based on the first predicate and filtered first data from the application of the dynamic predicate. Related systems and articles of manufacture are provided.

Disclosed herein are system, method, and computer tangible medium embodiments for generating a relational database model from a model view that provides an estimate for generating query plan for a query on the model view, according to an embodiment. A join model of a model view set on one or more database tables is received. At least one index conversion of the join model is performed, where the index conversion converts at least one index in the join model into at least one leaf node in a relational model tree. At least one join conversion of the join model is performed where the at least one join conversion generates a node in the relational model tree that joins a first and second leaf nodes in the relational model tree. A requested parameter conversion is performed, where the requested parameter conversion includes an attribute or key figure requested by a query.

Conversion of model views into relational models

A method may include inserting, into a hash trie, data records from a database table. The inserting may include traversing the hash trie to identify, for each data record included in the database table, a corresponding node at which to insert the data record. The hash trie may be traversed based on a hash of a key value associated with each data record. The node at which to insert a data record may be identified based on an offset forming a binary representation of the hash of a key value associated with that data record. The offset may include a portion of a plurality of binary digits forming the binary representation. A data record may be inserted at a corresponding node by updating a data structure included at the node. A database operation may be performed based on the hash trie filled with the data records from the database table.

Hash trie based optimization of database operations

A join operation between split data tables includes providing reduction data from first partitions to each partition among second partitions. The reduction data serves to identify actual values in one of the second partitions that also occur in one of the first partitions. Global IDs are assigned. Translation lists including the global IDs are sent to the first partitions. Each first partition and each second partition create globalized lists which can then be combined to generate respective first and second compiled lists. The join operation can then be conducted on the first and second compiled lists.

Equi-joins between split tables

A system for generating a query plan is provided. In some implementations, the system performs operations comprising: determining that a first query operation is a full table query operation, the full table query operation comprising a query operation operating on a database table as a whole; determining that a second query operation is a split table query operation, the split table query operation comprising a plurality of parallel query operations each operating on a portion of the database table; and inserting, based on the first query operation being a full table query operation and the second query operation being a split table query operation, a switch operation between the first and the second query operation, the switch operation being configured to distribute data output by the first query operation to the plurality of parallel query operations comprising the second query operation. Related methods and articles of manufacture are also described.

Query plan generation for split table query operations

A system for generating a query plan is provided. In some implementations, the system performs operations comprising: translating, into corresponding code, a query operation in a query plan comprising a sequence of query operations; determining a context for the translating of the query operation, the context corresponding to whether the query operation comprises a pre-compiled query operation or a code-generating query operation; and inserting adaptor code between code for the query operation and code for one or more previous query operations in the sequence of query operations, when a change in context is detected between the translating of the query operation and a translation of the one or more previous query operations. Related methods and articles of manufacture are also described.

Query plan generation for precompiled and code generating query operations

Technologies for performing garbage collection in database systems, such as multi-version concurrency control (MVCC) database systems, are described. For example, different garbage collection techniques can be used separately or in various combinations, including interval garbage collection, group garbage collection, table garbage collection, and combinations. For example, a particular type of combination, called hybrid garbage collection, uses technique from interval garbage collection and group garbage collection, or from interval, group, and table garbage collection.

Interval garbage collection for multi-version concurrency control in database systems

Partitioning of source partitions of a table of a database to target partitions is initiated. Thereafter, a transition partition specification is specified that identifies the source partitions and the target partitions. Data is then moved (e.g., asynchronously moved, etc.) from the source partitions to the target partitions. Concurrently with the moving of the data, operates are handled using the transition partition specification. Subsequently, the source partitions are dropped when all of the data has been moved to the target partitions and there are no open transactions accessing the source partitions. Related apparatus, systems, techniques and articles are also described.

Database table re-partitioning using two active partition specifications

A join operation between split data tables includes providing value IDs. For each of the value IDs, a unique global ID may be associated with the value ID when the actual value represented by the value ID occurs among actual values comprising the second attribute of the second partition. For each identified unique global ID, the identified unique global ID may be paired with a document ID of a data record contained in a second partition stored at the second server in which the actual value in the data record is represented by the value ID associated with the identified unique global ID.

Methods and apparatus, including computer program products, for selection of rows and values from indexes with updates. In general, rows of an index may be associated with validity flags that indicate whether a row has been updated with an update inserted in a delta index; one scheme for value identifiers may be used for an index and another scheme for one or more delta indexes where all of the indexes are, to at least some extent, compressed according to dictionary-based compression; and multiple delta indexes may be used in alternation such that one delta index may accept updates while another is being updated. The delta indexes may also have validity flags and all updates, such as modifications of values, deletion of records, and inserting of new records may be handled as updates accepted by one or more delta indexes.

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Heidelberg, Germany

Wolfgang Stephan