X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Ffiles.texi;h=ae10ec7aa1dbbc49383e9914320cb3bc2ba37f24;hb=67ab7839678c0f8aa12459ce5a585a5636f20196;hp=df01567eb956efd64df16ca7feff2e4fba3e93e9;hpb=dde7b813c5747fba5d14e47f6dd82bb7b4dc7cf1;p=pspp diff --git a/doc/files.texi b/doc/files.texi index df01567eb9..ae10ec7aa1 100644 --- a/doc/files.texi +++ b/doc/files.texi @@ -39,25 +39,46 @@ Only variables with names that exist in both the active file and the system file are considered. Variables with the same name but different types (numeric, string) will cause an error message. Otherwise, the system file variables' attributes will replace those in their matching -active file variables, as described below. +active file variables: +@itemize @bullet +@item If a system file variable has a variable label, then it will replace the active file variable's variable label. If the system file variable does not have a variable label, then the active file variable's variable -label, if any, will be retained. +label, if any, will be retained. + +@item +If the system file variable has custom attributes (@pxref{VARIABLE +ATTRIBUTE}), then those attributes replace the active file variable's +custom attributes. If the system file variable does not have custom +attributes, then the active file variable's custom attributes, if any, +will be retained. +@item If the active file variable is numeric or short string, then value labels and missing values, if any, will be copied to the active file variable. If the system file variable does not have value labels or missing values, then those in the active file variable, if any, will not be disturbed. +@end itemize + +In addition to properties of variables, some properties of the active +file dictionary as a whole are updated: -Finally, weighting of the active file is updated (@pxref{WEIGHT}). If -the active file has a weighting variable, and the system file does not, -or if the weighting variable in the system file does not exist in the -active file, then the active file weighting variable, if any, is -retained. Otherwise, the weighting variable in the system file becomes -the active file weighting variable. +@itemize @bullet +@item +If the system file has custom attributes (@pxref{DATAFILE ATTRIBUTE}), +then those attributes replace the active file variable's custom +attributes. + +@item +If the active file has a weighting variable (@pxref{WEIGHT}), and the +system file does not, or if the weighting variable in the system file +does not exist in the active file, then the active file weighting +variable, if any, is retained. Otherwise, the weighting variable in +the system file becomes the active file weighting variable. +@end itemize @cmd{APPLY DICTIONARY} takes effect immediately. It does not read the active @@ -265,7 +286,8 @@ GET DATA /TYPE=PSQL /CONNECT=@{connection info@} /SQL=@{query@} [/ASSUMEDVARWIDTH=n] - [/UNENCRYPTED]. + [/UNENCRYPTED] + [/BSIZE=n]. @end display @cindex postgres @@ -303,6 +325,17 @@ Whether or not the connection is encrypted depends upon the underlying psql library and the capabilities of the database server. +The BSIZE subcommand serves only to optimise the speed of data transfer. +It specifies an upper limit on +number of cases to fetch from the database at once. +The default value is 4096. +If your SQL statement fetches a large number of cases but only a small number of +variables, then the data transfer may be faster if you increase this value. +Conversely, if the number of variables is large, or if the machine on which +PSPP is running has only a +small amount of memory, then a smaller value will be better. + + The following syntax is an example: @example GET DATA /TYPE=PSQL @@ -373,7 +406,7 @@ GET DATA /TYPE=TXT [/IMPORTCASE=@{ALL,FIRST max_cases,PERCENT percent@}] /DELIMITERS="delimiters" - [/QUALIFIER="quote"] + [/QUALIFIER="quotes" [/ESCAPE]] [/DELCASE=@{LINE,VARIABLES n_variables@}] /VARIABLES=del_var [del_var]@dots{} where each del_var takes the form: @@ -405,11 +438,22 @@ delimiter, immediately following @samp{\t}. To read a data file in which each field appears on a separate line, specify the empty string for DELIMITERS. -The optional QUALIFIER subcommand names a character that can be used -to quote values within fields in the input. A field that begins with -the specified quote character ends at the next match quote. -Intervening delimiters become part of the field, instead of -terminating it. +The optional QUALIFIER subcommand names one or more characters that +can be used to quote values within fields in the input. A field that +begins with one of the specified quote characters ends at the next +matching quote. Intervening delimiters become part of the field, +instead of terminating it. The ability to specify more than one quote +character is a PSPP extension. + +By default, a character specified on QUALIFIER cannot itself be +embedded within a field that it quotes, because the quote character +always terminates the quoted field. With ESCAPE, however, a doubled +quote character within a quoted field inserts a single instance of the +quote into the field. For example, if @samp{'} is specified on +QUALIFIER, then without ESCAPE @code{'a''b'} specifies a pair of +fields that contain @samp{a} and @samp{b}, but with ESCAPE it +specifies a single field that contains @samp{a'b}. ESCAPE is a PSPP +extension. The DELCASE subcommand controls how data may be broken across lines in the data file. With LINE, the default setting, each line must contain @@ -483,12 +527,12 @@ GET DATA /TYPE=TXT /FILE='cars.data' /DELIMITERS=' ' /FIRSTCASE=2 Consider the following information on animals in a pet store: @example -"Pet Name", "Age", "Color", "Date Received", "Price", "Needs Walking", "Type" +'Pet''s Name', "Age", "Color", "Date Received", "Price", "Height", "Type" , (Years), , , (Dollars), , -"Rover", 4.5, Brown, "12 Feb 2004", 80, True, "Dog" -"Charlie", , Gold, "5 Apr 2007", 12.3, False, "Fish" -"Molly", 2, Black, "12 Dec 2006", 25, False, "Cat" -"Gilly", , White, "10 Apr 2007", 10, False, "Guinea Pig" +"Rover", 4.5, Brown, "12 Feb 2004", 80, '1''4"', "Dog" +"Charlie", , Gold, "5 Apr 2007", 12.3, "3""", "Fish" +"Molly", 2, Black, "12 Dec 2006", 25, '5"', "Cat" +"Gilly", , White, "10 Apr 2007", 10, "3""", "Guinea Pig" @end example @noindent @@ -497,15 +541,15 @@ The following syntax can be used to read the pet store data: @c If you change this example, change the regression test in @c tests/command/get-data-txt-examples.sh to match. @example -GET DATA /TYPE=TXT /FILE='pets.data' /DELIMITERS=', ' /QUALIFIER='"' +GET DATA /TYPE=TXT /FILE='pets.data' /DELIMITERS=', ' /QUALIFIER='''"' /ESCAPE /FIRSTCASE=3 /VARIABLES=name A10 age F3.1 color A5 received EDATE10 price F5.2 - needs_walking A5 - type A10. + height a5 + type a10. @end example @node GET DATA /TYPE=TXT /ARRANGEMENT=FIXED