Describes a well log data block. The number of data rows in the persistent block. If a value is specified for this element in a query then the server will limit the number of data rows in the result but the return value will still be the number of data rows in the persistent block. Identifies the pass within the run. A description of the block. For example, 'main log section', 'repeat section', 'logged going in hole' 'main log section, curve group 1', 'composite'. Primary index type. The index may be a quantity type or it may be a dateTime type. At least one of the index sets must be given. If both are given then "indexType" and "indexCurve" must represent an elapsed time from "startDateTimeIndex". The start and end indexes are server query parameters and will be populated with valid values in a GetFromStore result. When the direction is defined as "Increasing", the startIndex is the starting (minimum) index value at which the first data point is located. When the log header defines the direction as "Decreasing", the startIndex is the starting (maximum) index value at which the first data point is located. When the direction is defined as "Increasing", the endIndex is the ending (maximum) index value at which the last data point is located. When the log header defines the direction as Decreasing, the endIndex is the ending (minimum) index value at which the last data point is located. The sampling increment. Set to zero for unequal sampling. For curves that are originally sampled at a constant increment, this value should be retained because calculated values may have cumulative errors. When the direction is defined as "Increasing", the startIndex is the starting (minimum) index value at which the first data point is located. When the log header defines the direction as "Decreasing", the startIndex is the starting (maximum) index value at which the first data point is located. When the direction is defined as "Increasing", the endIndex is the ending (maximum) index value at which the last data point is located. When the log header defines the direction as Decreasing, the endIndex is the ending (minimum) index value at which the last data point is located. This value is optional when startDateTimeIndex represents a reference for elapsed times. Otherwise, it should be defined when startDateTimeIndex is defined. The polarity of change in index values associated with successive data records. Increasing or Decreasing. Mixed is not a valid value. The mnemonic of the index curve plus the column index. A column index of zero indicates an implied trace whose values start at startIndex and increment by stepIncrement for each row. An empty string is the default representation of a null value for a curve (i.e. when the null value representation is not explicitly defined). If a null value representation is defined for a log, this becomes the default for all curves in that log (but can be overridden at the block or curve level). An empty string is always a valid null value representation in the comma delimited list. An empty string is not a valid null value representation within a space delimited or base64 encoded array. Specifying a null value also makes it easier to transform data back to a legacy format without having to scan the data to insure that the null pattern does not exist in the data. Log parameters that apply to this block. A curve occurring in data records defined by this block, and its position within the data record. Each curve in the block must have a different mnemonic. Unique identifier for the block. This value must be unique within the context of the wellLog. This value will be pointed to by data levels that are associated with this block.