doc/man1/htsn-import.1

   1 .TH htsn-import 1
   2
   3 .SH NAME
   4 htsn-import \- Import XML files from The Sports Network into an RDBMS.
   5
   6 .SH SYNOPSIS
   7
   8 \fBhtsn-import\fR [OPTIONS] [FILES]
   9
  10 .SH DESCRIPTION
  11 .P
  12 The Sports Network <http://www.sportsnetwork.com/> offers an XML feed
  13 containing various sports news and statistics. Our sister program
  14 \fBhtsn\fR is capable of retrieving the feed and saving the individual
  15 XML documents contained therein. But what to do with them?
  16 .P
  17 The purpose of \fBhtsn-import\fR is to take these XML documents and
  18 get them into something we can use, a relational database management
  19 system (RDBMS), otherwise known as a SQL database. The structure of
  20 relational database, is, well, relational, and the feed XML is not. So
  21 there is some work to do before the data can be imported into the
  22 database.
  23 .P
  24 First, we must parse the XML. Each supported document type (see below)
  25 has a full pickle/unpickle implementation (\(dqpickle\(dq is simply a
  26 synonym for serialize here). That means that we parse the entire
  27 document into a data structure, and if we pickle (serialize) that data
  28 structure, we get the exact same XML document tha we started with.
  29 .P
  30 This is important for two reasons. First, it serves as a second level
  31 of validation. The first validation is performed by the XML parser,
  32 but if that succeeds and unpicking fails, we know that something is
  33 fishy. Second, we don't ever want to be surprised by some new element
  34 or attribute showing up in the XML. The fact that we can unpickle the
  35 whole thing now means that we won't be surprised in the future.
  36 .P
  37 The aforementioned feature is especially important because we
  38 automatically migrate the database schema every time we import a
  39 document. If you attempt to import a \(dqnewsxml.dtd\(dq document, all
  40 database objects relating to the news will be created if they do not
  41 exist. We don't want the schema to change out from under us without
  42 warning, so it's important that no XML be parsed that would result in
  43 a different schema than we had previously. Since we can
  44 pickle/unpickle everything already, this should be impossible.
  45
  46 .SH SUPPORTED DOCUMENT TYPES
  47 .P
  48 The XML document types obtained from the feed are uniquely identified
  49 by their DTDs. We currently support documents with the following DTDs:
  50 .IP \[bu] 2
  51 AutoRacingResultsXML.dtd
  52 .IP \[bu]
  53 Auto_Racing_Schedule_XML.dtd
  54 .IP \[bu]
  55 Heartbeat.dtd
  56 .IP \[bu]
  57 Injuries_Detail_XML.dtd
  58 .IP \[bu]
  59 injuriesxml.dtd
  60 .IP \[bu]
  61 newsxml.dtd
  62 .IP \[bu]
  63 Odds_XML.dtd
  64 .IP \[bu]
  65 scoresxml.dtd
  66 .IP \[bu]
  67 weatherxml.dtd
  68 .IP \[bu]
  69 GameInfo
  70 .RS
  71 .IP \[bu]
  72 CBASK_Lineup_XML.dtd
  73 .IP \[bu]
  74 cbaskpreviewxml.dtd
  75 .IP \[bu]
  76 cflpreviewxml.dtd
  77 .IP \[bu]
  78 Matchup_NBA_NHL_XML.dtd
  79 .IP \[bu]
  80 MLB_Gaming_Matchup_XML.dtd
  81 .IP \[bu]
  82 MLB_Lineup_XML.dtd
  83 .IP \[bu]
  84 MLB_Matchup_XML.dtd
  85 .IP \[bu]
  86 MLS_Preview_XML.dtd
  87 .IP \[bu]
  88 mlbpreviewxml.dtd
  89 .IP \[bu]
  90 NBA_Gaming_Matchup_XML.dtd
  91 .IP \[bu]
  92 NBA_Playoff_Matchup_XML.dtd
  93 .IP \[bu]
  94 NBALineupXML.dtd
  95 .IP \[bu]
  96 nbapreviewxml.dtd
  97 .IP \[bu]
  98 NCAA_FB_Preview_XML.dtd
  99 .IP \[bu]
 100 NFL_NCAA_FB_Matchup_XML.dtd
 101 .IP \[bu]
 102 nflpreviewxml.dtd
 103 .IP \[bu]
 104 nhlpreviewxml.dtd
 105 .IP \[bu]
 106 recapxml.dtd
 107 .IP \[bu]
 108 WorldBaseballPreviewXML.dtd
 109 .RE
 110 .IP \[bu]
 111 SportInfo
 112 .RS
 113 .IP \[bu]
 114 CBASK_3PPctXML.dtd
 115 .IP \[bu]
 116 Cbask_All_Tourn_Teams_XML.dtd
 117 .IP \[bu]
 118 CBASK_AssistsXML.dtd
 119 .IP \[bu]
 120 Cbask_Awards_XML.dtd
 121 .IP \[bu]
 122 CBASK_BlocksXML.dtd
 123 .IP \[bu]
 124 Cbask_Conf_Standings_XML.dtd
 125 .IP \[bu]
 126 Cbask_DivII_III_Indv_Stats_XML.dtd
 127 .IP \[bu]
 128 Cbask_DivII_Team_Stats_XML.dtd
 129 .IP \[bu]
 130 Cbask_DivIII_Team_Stats_XML.dtd
 131 .IP \[bu]
 132 CBASK_FGPctXML.dtd
 133 .IP \[bu]
 134 CBASK_FoulsXML.dtd
 135 .IP \[bu]
 136 CBASK_FTPctXML.dtd
 137 .IP \[bu]
 138 Cbask_Indv_Scoring_XML.dtd
 139 .IP \[bu]
 140 CBASK_MinutesXML.dtd
 141 .IP \[bu]
 142 Cbask_Polls_XML.dtd
 143 .IP \[bu]
 144 CBASK_ReboundsXML.dtd
 145 .IP \[bu]
 146 CBASK_ScoringLeadersXML.dtd
 147 .IP \[bu]
 148 Cbask_Team_ThreePT_Made_XML.dtd
 149 .IP \[bu]
 150 Cbask_Team_ThreePT_PCT_XML.dtd
 151 .IP \[bu]
 152 Cbask_Team_Win_Pct_XML.dtd
 153 .IP \[bu]
 154 Cbask_Top_Twenty_Five_XML.dtd
 155 .IP \[bu]
 156 CBASK_TopTwentyFiveResult_XML.dtd
 157 .IP \[bu]
 158 Cbask_Tourn_Awards_XML.dtd
 159 .IP \[bu]
 160 Cbask_Tourn_Champs_XML.dtd
 161 .IP \[bu]
 162 Cbask_Tourn_Indiv_XML.dtd
 163 .IP \[bu]
 164 Cbask_Tourn_Leaders_XML.dtd
 165 .IP \[bu]
 166 Cbask_Tourn_MVP_XML.dtd
 167 .IP \[bu]
 168 Cbask_Tourn_Records_XML.dtd
 169 .IP \[bu]
 170 LeagueScheduleXML.dtd
 171 .IP \[bu]
 172 minorscoresxml.dtd
 173 .RE
 174 .P
 175 The GameInfo and SportInfo types do not have their own top-level
 176 tables in the database. Instead, their raw XML is stored in either the
 177 \(dqgame_info\(dq or \(dqsport_info\(dq table respectively.
 178
 179 .SH DATABASE SCHEMA
 180 .P
 181 At the top level (with two notable exceptions), we have one table for
 182 each of the XML document types that we import. For example, the
 183 documents corresponding to \fInewsxml.dtd\fR will have a table called
 184 \(dqnews\(dq. All top-level tables contain two important fields,
 185 \(dqxml_file_id\(dq and \(dqtime_stamp\(dq. The former is unique and
 186 prevents us from inserting the same data twice. The time stamp on the
 187 other hand lets us know when the data is old and can be removed. The
 188 database schema make it possible to delete only the outdated top-level
 189 records; all transient children should be removed by triggers.
 190 .P
 191 These top-level tables will often have children. For example, each
 192 news item has zero or more locations associated with it. The child
 193 table will be named <parent>_<children>, which in this case
 194 corresponds to \(dqnews_locations\(dq.
 195 .P
 196 To relate the two, a third table may exist with name
 197 <parent>__<child>. Note the two underscores. This prevents ambiguity
 198 when the child table itself contains underscores. The table joining
 199 \(dqnews\(dq with \(dqnews_locations\(dq is thus called
 200 \(dqnews__news_locations\(dq. This is necessary when the child table
 201 has a unique constraint; we don't want to blindly insert duplicate
 202 records keyed to the parent. Instead we'd like to use the third table
 203 to map an existing child to the new parent.
 204 .P
 205 Where it makes sense, children are kept unique to prevent pointless
 206 duplication. This slows down inserts, and speeds up reads (which are
 207 much more frequent). There is a tradeoff to be made, however. For a
 208 table with a small, fixed upper bound on the number of rows (like
 209 \(dqodds_casinos\(dq), there is great benefit to de-duplication. The
 210 total number of rows stays small, so inserts are still quick, and many
 211 duplicate rows are eliminated.
 212 .P
 213 But, with a table like \(dqodds_games\(dq, the number of games grows
 214 quickly and without bound. It is therefore more beneficial to be able
 215 to delete the old games (through an ON DELETE CASCADE, tied to
 216 \(dqodds\(dq) than it is to eliminate duplication. A table like
 217 \(dqnews_locations\(dq is somewhere in-between. It is hoped that the
 218 unique constraint in the top-level table's \(dqxml_file_id\(dq will
 219 prevent duplication in this case anyway.
 220 .P
 221 The aforementioned exceptions are the \(dqgame_info\(dq and
 222 \(dqsport_info\(dq tables. These tables contain the raw XML for a
 223 number of DTDs that are not handled individually. This is partially
 224 for backwards-compatibility with a legacy implementation, but is
 225 mostly a stopgap due to a lack of resources at the moment. These two
 226 tables (game_info and sport_info) still possess timestamps that allow
 227 us to prune old data.
 228 .P
 229 UML diagrams of the resulting database schema for each XML document
 230 type are provided with the \fBhtsn-import\fR documentation.
 231
 232 .SH XML Schema Oddities
 233 .P
 234 There are a number of problems with the XML on the wire. Even if we
 235 construct the DTDs ourselves, the results are sometimes
 236 inconsistent. Here we document a few of them.
 237
 238 .IP \[bu] 2
 239 Odds_XML.dtd
 240
 241 The <Notes> elements here are supposed to be associated with a set of
 242 <Game> elements, but since the pair
 243 (<Notes>...</Notes><Game>...</Game>) can appear zero or more times,
 244 this leads to ambiguity in parsing. We therefore ignore the notes
 245 entirely (although a hack is employed to facilitate parsing).
 246
 247 .IP \[bu]
 248 weatherxml.dtd
 249
 250 There appear to be two types of weather documents; the first has
 251 <listing> contained within <forecast> and the second has <forecast>
 252 contained within <listing>. While it would be possible to parse both,
 253 it would greatly complicate things. The first form is more common, so
 254 that's all we support for now.
 255
 256 .SH OPTIONS
 257
 258 .IP \fB\-\-backend\fR,\ \fB\-b\fR
 259 The RDBMS backend to use. Valid choices are \fISqlite\fR and
 260 \fIPostgres\fR. Capitalization is important, sorry.
 261
 262 Default: Sqlite
 263
 264 .IP \fB\-\-connection-string\fR,\ \fB\-c\fR
 265 The connection string used for connecting to the database backend
 266 given by the \fB\-\-backend\fR option. The default is appropriate for
 267 the \fISqlite\fR backend.
 268
 269 Default: \(dq:memory:\(dq
 270
 271 .IP \fB\-\-log-file\fR
 272 If you specify a file here, logs will be written to it (possibly in
 273 addition to syslog). Can be either a relative or absolute path. It
 274 will not be auto-rotated; use something like logrotate for that.
 275
 276 Default: none
 277
 278 .IP \fB\-\-log-level\fR
 279 How verbose should the logs be? We log notifications at four levels:
 280 DEBUG, INFO, WARN, and ERROR. Specify the \(dqmost boring\(dq level of
 281 notifications you would like to receive (in all-caps); more
 282 interesting notifications will be logged as well. The debug output is
 283 extremely verbose and will not be written to syslog even if you try.
 284
 285 Default: INFO
 286
 287 .IP \fB\-\-remove\fR,\ \fB\-r\fR
 288 Remove successfully processed files. If you enable this, you can see
 289 at a glance which XML files are not being processed, because they're
 290 all that should be left.
 291
 292 Default: disabled
 293
 294 .IP \fB\-\-syslog\fR,\ \fB\-s\fR
 295 Enable logging to syslog. On Windows this will attempt to communicate
 296 (over UDP) with a syslog daemon on localhost, which will most likely
 297 not work.
 298
 299 Default: disabled
 300
 301 .SH CONFIGURATION FILE
 302 .P
 303 Any of the command-line options mentioned above can be specified in a
 304 configuration file instead. We first look for \(dqhtsn-importrc\(dq in
 305 the system configuration directory. We then look for a file named
 306 \(dq.htsn-importrc\(dq in the user's home directory. The latter will
 307 override the former.
 308 .P
 309 The user's home directory is simply $HOME on Unix; on Windows it's
 310 wherever %APPDATA% points. The system configuration directory is
 311 determined by Cabal; the \(dqsysconfdir\(dq parameter during the
 312 \(dqconfigure\(dq step is used.
 313 .P
 314 The file's syntax is given by examples in the htsn-importrc.example file
 315 (included with \fBhtsn-import\fR).
 316 .P
 317 Options specified on the command-line override those in either
 318 configuration file.
 319
 320 .SH EXAMPLES
 321 .IP \[bu] 2
 322 Import newsxml.xml into a preexisting sqlite database named \(dqfoo.sqlite3\(dq:
 323
 324 .nf
 325 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 326 .I "              test/xml/newsxml.xml"
 327 Successfully imported test/xml/newsxml.xml.
 328 Imported 1 document(s) total.
 329 .fi
 330 .IP \[bu]
 331 Repeat the previous example, but delete newsxml.xml afterwards:
 332
 333 .nf
 334 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 335 .I "              --remove test/xml/newsxml.xml"
 336 Successfully imported test/xml/newsxml.xml.
 337 Imported 1 document(s) total.
 338 Removed processed file test/xml/newsxml.xml.
 339 .fi
 340 .IP \[bu]
 341 Use a Postgres database instead of the default Sqlite. This assumes
 342 that you have a database named \(dqhtsn\(dq accessible to user
 343 \(dqpostgres\(dq locally:
 344
 345 .nf
 346 .I $ htsn-import --connection-string='dbname=htsn user=postgres' \\\\
 347 .I "              --backend=Postgres test/xml/newsxml.xml"
 348 Successfully imported test/xml/newsxml.xml.
 349 Imported 1 document(s) total.
 350 .fi
 351
 352 .SH BUGS
 353
 354 .P
 355 Send bugs to michael@orlitzky.com.