The SQL Compiler determines the most efficient approach for satisfying the SQL statement and produces a section to implement this plan. A section is an efficient way to express the logic needed for a SQL statement because it does so directly in terms of specific DB2 UDB internal functions. The contents of a section deal with the bare essentials and the physical realities of the storage mechanisms used for the data.
By removing the levels of abstraction provided by SQL, a section can ensure the best performance during the execution of the statement. A SQL statement deals with a specific result set or target set; a set can consist of any number of rows and is treated as a whole by SQL. That is, SQL only recognizes sets of data, not individual rows.
Because a section is physically accessing the data as individual rows, it has control at that level. Each step in a section is based on what to do with the current row. The section returns data to the application on a row-by-row basis. Finally, by stripping away the abstraction of the SQL statement, a section allows the SQL statement and its result set to be represented by many different SQL methods getting that result set.
Each individual section is a product of the environment in which it is compiled. This flexibility is valuable when supporting static and dynamic SQL created at different times in different contexts. Although these two steps are sometimes combined into one from the user's perspective, they are actually two distinctly different steps from DB2 UDB's point of view.
Precompilation occurs when application source files containing SQL statements and host variables are submitted to a precompiler. A precompiler is specific to a programming language. Its job is to parse the application source to find any SQL statements and host variables, remove them, and then replace them in the source file with function calls and variables suitable to the programming language being used. The end result of precompilation is a modified version of the source file and the extracted SQL statements and variables.
The latter can be stored in a file, called a bindfile. This information can come directly from the precompilation step or from a bindfile. The process of creating a section from a SQL statement is referred to as compilation. It can also be referred to as optimization or preparing. The processes explained here apply to static and dynamic SQL statements. The differences between these two processes arise when compilation occurs and the values are used for the compilation environment.
Static SQL bases its compilation environment purely on the package information. The first step in the compilation of a SQL statement is the parsing stage. Data Connectivity Web Experience. Read next. Lost in Data Sources? Comments are disabled in preview mode. Follow us via RSS Feed. Georgia and S. Sandwich Is. Helena St. Pierre and Miquelon St. However, it can be referred to add a registry entry for any Database driver. Yes, Informatica version According to the Data Direct KB link below , two new connection options MultiSubnetFailover and ApplicationIntent have been added to the hotfix version of the driver Versions of Informatica earlier than Load of DWsqls A Socket closed error means that the connection has been terminated.
There can be a number of reasons for that, for example, network failure, the database unexpectedly terminated the connection, etc. Additional tracing of the network may be necessary to determine the cause of connection loss. Note that the Socket closed error indicates that the connection was lost outside of the control or awareness of the application or the driver used. Datadirect have recently certified EnterpriseDB Yes, it is possible.
Following are the details of the setup:. The driver may report one or both of the errors depending on the timeout setting and the usability of the connection. When the driver detects that the timeout has occurred, it will also try to determine if the connection is still valid and usable. If the driver determines that the connection is still usable the socket is not closed then it will report that the network operation has timed out.
If the driver determines that the connection is no longer valid, then it will report that the network operation has timed out and also that the connection is dead.
The "connection dead" error can appear by itself if the driver attempts to communicate with the server and discovers that the socket has been closed.
So, in the case where you are only seeing "Network Operation timed out", the driver has detected that the timeout has been reached but still considers the connection to be valid and usable. In the case where you are seeing both the "Network Operation timed out" and "Connection dead" together, the driver is timing out and also detects that the connection is no longer usable.
The driver determines whether a connection is valid by doing the following: The driver sends an interrupt to the server to determine whether the connection is valid. The interrupt is used to cancel the current request. If any of the following are true, then the connection is considered valid and usable:.
This is a known limitation and a FR has been submitted to include this feature in a future release. DataDirect is continuing research to determine if it can support this feature.
Yes, PowerCenter 9. This is not supported in prior versions. However, if there are issues in creating the packages automatically, it is recommended to check if the user has the necessary permissions to create the packages.
If you e nt e r a host nam e , th e driv e r must find this nam e with th e corr e ct addr e ss assignm e nt in th e HOSTS fil e on th e workstation or in a DNS s e rv e r.
Th e d e fault is localhost. Sp e cify e ith e r this port's num e ric addr e ss or its s e rvic e nam e. If you sp e cify a s e rvic e nam e , th e driv e r must find this nam e with th e corr e ct port assignm e nt in th e SERVICES fil e on th e workstation.
Th e d e fault is S e l e ct option 3 to display a list of activ e ports on th e DB2 for i machin e.
Typ e th e DB2 location nam e. Us e th e nam e d e fin e d during th e local DB2 installation. Typ e th e nam e of th e databas e to which you want to conn e ct. IMPORTANT: You must hav e all compon e nts of your databas e cli e nt softwar e install e d and conn e cting prop e rly; oth e rwis e , th e driv e r will not op e rat e corr e ctly.
Ch e ck with your databas e administrator for th e corr e ct numb e r. Th e d e fault is ORCL. This option and th e S e rvic e Nam e option ar e mutually e xclusiv e. If th e S e rvic e Nam e option is sp e cifi e d, do not sp e cify this option. Th e s e rvic e nam e is a string that is th e global databas e nam e —a nam e that is compris e d of th e databas e nam e and domain nam e , for e xampl e : sal e s.
This option and th e SID option ar e mutually e xclusiv e. If th e SID option is sp e cifi e d, do not sp e cify this option. Typ e th e nam e of th e Oracl e e dition that th e driv e r is to us e wh e n e stablishing a conn e ction. Oracl e 11 g R2 and high e r allows your databas e administrator to cr e at e multipl e e ditions of sch e ma obj e cts so that your application can still us e thos e obj e cts whil e th e databas e is b e ing upgrad e d.
This option t e lls th e driv e r which e dition of th e sch e ma obj e cts to us e. The Salesforce driver supports the standard SQL query language to fetch, insert, update, and delete data from Salesforce. Before you configure a data source for the Salesforce driver, you must set the PATH library path environment variable to the path of the jvm.
Otherwise, leave the field blank. NOTE: You must provide the following information in the logon dialog box:. Both the password and security token are case-sensitive. For e xampl e , you can e nt e r SybIQSs e rv e r, If you do not sp e cify a valu e , th e d e fault is th e databas e d e fin e d by th e syst e m administrator for e ach us e r. Your ODBC application may override this value or you may override it in the logon dialog box or connection string.
Using an IP addr e ss r e duc e s th e tim e it tak e s to conn e ct, but if that addr e ss is not availabl e at conn e ction tim e , th e conn e ction fails and th e driv e r do e s not att e mpt to fail ov e r to anoth e r addr e ss.
0コメント