Some of Teiid's low-level behavior can be configured via system properties, rather than through configuration files. A typical place to set system properties for JBoss AS launches is in the <jboss-install>/bin/<mode>.conf. A property setting has the format -Dproperty=value

• org.teiid.allowNanInfinity - defaults to false. Set to true to allow numeric functions to return NaN (Not A Number) and +-Infinity. Note that these values are not covered by the SQL specification.

• org.teiid.useValueCache - defaults to false. Set to true to enable the canonical value cache. Value caching is used dynamically when buffer memory is consumed to reuse identical values and thus reduce the memory consumed by Teiid. There is a computation cost associated with the cache lookup, so enabling this setting is not appropriate for installations handling large volumes of dissimilar data.

• org.teiid.ansiQuotedIdentifiers - defaults to true. Set to false to emulate Teiid 6.x and prior behavior of treating double quoted values without leading identifier parts as string literals, which is not expected by the SQL specification.

• org.teiid.subqueryUnnestDefault - defaults to false. Set to true to aggressively unnest subquery IN and EXISTS predicates. If possible the predicate will be unnested to a traditional join and will be eligible for dependent join planning. If a traditional join is not possible (such as with NOT IN) a merge join version of the semijoin or antijoin will be considered by upon the costing information available.

• org.teiid.ODBCPacketSize - defaults to 307200. Target size in bytes of the ODBC results buffer. This is not a hard maximum, lobs and wide rows may use larger buffers.

• org.teiid.decimalAsDouble - defaults to false. Set to true to parse exact fixed point literals, e.g. 1.0, as double values rather than as decimal/BigDecimal values and to return a double value from the AVG function for integral values in the same way as releases earlier than 8.0.

• org.teiid.comparableLobs - defaults to false. Set to true to allow blob and clob column values to be comparable in Teiid. Source type metadata will determine if the comparison can be pushed down.

• org.teiid.comparableObject - defaults to false. Set to true to allow object column values to be comparable in Teiid. Source type metadata will determine if the comparison can be pushed down. The object instances are expected to correctly implement java.lang.Comparable.compareTo. If the instance object is not Comparable, then ClassCastExceptions may the thrown.

• org.teiid.padSpace - defaults to false. Set to true to compare strings as if PAD SPACE collation is being used, that is strings are effectively right padded to the same length for comparison. If this property is set, it is not necessary to use the trimStrings translator option.

• org.teiid.collationLocale - not set by default, which means that Java's natural (UTF-16) string comparison will be used.  Set to a Java locale string language[_country[_varient]], where language, country, and variant are two letter codes - see java.util.Locale for more on valid codes.  Note that even if org.teiid.comparableLobs is set, clob values will not be compared using the locale collator.

• org.teiid.clientVdbLoadTimeoutMillis - defaults to 5 minutes. The default amount of time a client (currently only local clients) will wait to make a connection to an active VDB before throwing an exception. Clients may override this setting via the waitForLoad connection property.

• org.teiid.enDateNames - defaults to false. Set to true to use English month and day names for the system function dayName and monthName, rather than returning names from the Java default locale.  Prior to 8.2 dayName and monthName always returned English names.

• org.teiid.pushdownDefaultNullOrder - defaults to false. Set to true to mimic 8.1 and prior release behavior of pushing the Teiid's default null order of nulls low if the source has a different default null order and supports explicit null ordering.

• org.teiid.implicitMultiSourceJoin - defaults to true. Set to false to disable Teiid 8.2 and prior release behavior of implicitly partitioning joins between multi-source tables. When set to false and explicit predicate such as tbl1.source_name = tbl2.source_name is required to partition the results of the join.

• org.teiid.joinPrefetchBatches - defaults to 10. Sets the number of batches that can be pre-fetched/buffered for join processing that may otherwise just be streamed from the source. Consider increasing when you have slow ALREADY_SORTED sources participating in a non-dependent join that return significantly more batches. Note however that increasing this value can lead to an increase in disk utilization to perform the buffering.

• org.teiid.maxStringLength - defaults to 4000. Sets the nominal maximum length of strings in Teiid - most operations in Teiid will truncate strings that are larger than this value. Setting this value can also adjust the max size of lob bytes held in memory. NOTE: sources may not appropriately handle string values that are larger than the source supports.

  Strings are always fully held in memory. Do not set this value too high as you may experience out of memory errors.

• org.teiid.calendarTimestampDiff - defaults to true. Set to false to use the Teiid 8.2 and old computation of timestampdiff. NOTE: using the old behavior can result in differing results between pushed and non-pushed versions of timestampdiff for intervals greater than seconds as sources use date part and not approximate interval differences.

PostgreSQL Compatibility

• org.teiid.iso8601Week - defaults to false. Set to true to use ISO 8601 rules for week calculations regardless of the locale. When true the dayOfWeek function will begin with 1 for MONDAY rather than SUNDAY, and the week function will require that week 1 of a year contains the year's first Thursday.

• org.teiid.backslashDefaultMatchEscape - defaults to false. Set to true to use '\' as the default escape character for LIKE and SIMILAR TO predicates when no escape is specified. Otherwise Teiid assumes the SQL specification compliant behavior of treating each non-wildcard character as an exact match character.