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 .IP \[bu]
 174 Minor_Baseball_League_Leaders_XML.dtd
 175 .IP \[bu]
 176 Minor_Baseball_Standings_XML.dtd
 177 .IP \[bu]
 178 Minor_Baseball_Transactions_XML.dtd
 179 .IP \[bu]
 180 mlbbattingavgxml.dtd
 181 .IP \[bu]
 182 mlbdoublesleadersxml.dtd
 183 .IP \[bu]
 184 MLBGamesPlayedXML.dtd
 185 .IP \[bu]
 186 MLBGIDPXML.dtd
 187 .IP \[bu]
 188 MLBHitByPitchXML.dtd
 189 .IP \[bu]
 190 mlbhitsleadersxml.dtd
 191 .IP \[bu]
 192 mlbhomerunsxml.dtd
 193 .IP \[bu]
 194 MLBHRFreqXML.dtd
 195 .IP \[bu]
 196 MLBIntWalksXML.dtd
 197 .IP \[bu]
 198 MLBKORateXML.dtd
 199 .IP \[bu]
 200 mlbonbasepctxml.dtd
 201 .IP \[bu]
 202 MLBOPSXML.dtd
 203 .IP \[bu]
 204 MLBPlateAppsXML.dtd
 205 .IP \[bu]
 206 mlbrbisxml.dtd
 207 .IP \[bu]
 208 mlbrunsleadersxml.dtd
 209 .RE
 210 .P
 211 The GameInfo and SportInfo types do not have their own top-level
 212 tables in the database. Instead, their raw XML is stored in either the
 213 \(dqgame_info\(dq or \(dqsport_info\(dq table respectively.
 214
 215 .SH DATABASE SCHEMA
 216 .P
 217 At the top level (with two notable exceptions), we have one table for
 218 each of the XML document types that we import. For example, the
 219 documents corresponding to \fInewsxml.dtd\fR will have a table called
 220 \(dqnews\(dq. All top-level tables contain two important fields,
 221 \(dqxml_file_id\(dq and \(dqtime_stamp\(dq. The former is unique and
 222 prevents us from inserting the same data twice. The time stamp on the
 223 other hand lets us know when the data is old and can be removed. The
 224 database schema make it possible to delete only the outdated top-level
 225 records; all transient children should be removed by triggers.
 226 .P
 227 These top-level tables will often have children. For example, each
 228 news item has zero or more locations associated with it. The child
 229 table will be named <parent>_<children>, which in this case
 230 corresponds to \(dqnews_locations\(dq.
 231 .P
 232 To relate the two, a third table may exist with name
 233 <parent>__<child>. Note the two underscores. This prevents ambiguity
 234 when the child table itself contains underscores. The table joining
 235 \(dqnews\(dq with \(dqnews_locations\(dq is thus called
 236 \(dqnews__news_locations\(dq. This is necessary when the child table
 237 has a unique constraint; we don't want to blindly insert duplicate
 238 records keyed to the parent. Instead we'd like to use the third table
 239 to map an existing child to the new parent.
 240 .P
 241 Where it makes sense, children are kept unique to prevent pointless
 242 duplication. This slows down inserts, and speeds up reads (which are
 243 much more frequent). There is a tradeoff to be made, however. For a
 244 table with a small, fixed upper bound on the number of rows (like
 245 \(dqodds_casinos\(dq), there is great benefit to de-duplication. The
 246 total number of rows stays small, so inserts are still quick, and many
 247 duplicate rows are eliminated.
 248 .P
 249 But, with a table like \(dqodds_games\(dq, the number of games grows
 250 quickly and without bound. It is therefore more beneficial to be able
 251 to delete the old games (through an ON DELETE CASCADE, tied to
 252 \(dqodds\(dq) than it is to eliminate duplication. A table like
 253 \(dqnews_locations\(dq is somewhere in-between. It is hoped that the
 254 unique constraint in the top-level table's \(dqxml_file_id\(dq will
 255 prevent duplication in this case anyway.
 256 .P
 257 The aforementioned exceptions are the \(dqgame_info\(dq and
 258 \(dqsport_info\(dq tables. These tables contain the raw XML for a
 259 number of DTDs that are not handled individually. This is partially
 260 for backwards-compatibility with a legacy implementation, but is
 261 mostly a stopgap due to a lack of resources at the moment. These two
 262 tables (game_info and sport_info) still possess timestamps that allow
 263 us to prune old data.
 264 .P
 265 UML diagrams of the resulting database schema for each XML document
 266 type are provided with the \fBhtsn-import\fR documentation.
 267
 268 .SH XML Schema Oddities
 269 .P
 270 There are a number of problems with the XML on the wire. Even if we
 271 construct the DTDs ourselves, the results are sometimes
 272 inconsistent. Here we document a few of them.
 273
 274 .IP \[bu] 2
 275 Odds_XML.dtd
 276
 277 The <Notes> elements here are supposed to be associated with a set of
 278 <Game> elements, but since the pair
 279 (<Notes>...</Notes><Game>...</Game>) can appear zero or more times,
 280 this leads to ambiguity in parsing. We therefore ignore the notes
 281 entirely (although a hack is employed to facilitate parsing).
 282
 283 .IP \[bu]
 284 weatherxml.dtd
 285
 286 There appear to be two types of weather documents; the first has
 287 <listing> contained within <forecast> and the second has <forecast>
 288 contained within <listing>. While it would be possible to parse both,
 289 it would greatly complicate things. The first form is more common, so
 290 that's all we support for now.
 291
 292 .SH OPTIONS
 293
 294 .IP \fB\-\-backend\fR,\ \fB\-b\fR
 295 The RDBMS backend to use. Valid choices are \fISqlite\fR and
 296 \fIPostgres\fR. Capitalization is important, sorry.
 297
 298 Default: Sqlite
 299
 300 .IP \fB\-\-connection-string\fR,\ \fB\-c\fR
 301 The connection string used for connecting to the database backend
 302 given by the \fB\-\-backend\fR option. The default is appropriate for
 303 the \fISqlite\fR backend.
 304
 305 Default: \(dq:memory:\(dq
 306
 307 .IP \fB\-\-log-file\fR
 308 If you specify a file here, logs will be written to it (possibly in
 309 addition to syslog). Can be either a relative or absolute path. It
 310 will not be auto-rotated; use something like logrotate for that.
 311
 312 Default: none
 313
 314 .IP \fB\-\-log-level\fR
 315 How verbose should the logs be? We log notifications at four levels:
 316 DEBUG, INFO, WARN, and ERROR. Specify the \(dqmost boring\(dq level of
 317 notifications you would like to receive (in all-caps); more
 318 interesting notifications will be logged as well. The debug output is
 319 extremely verbose and will not be written to syslog even if you try.
 320
 321 Default: INFO
 322
 323 .IP \fB\-\-remove\fR,\ \fB\-r\fR
 324 Remove successfully processed files. If you enable this, you can see
 325 at a glance which XML files are not being processed, because they're
 326 all that should be left.
 327
 328 Default: disabled
 329
 330 .IP \fB\-\-syslog\fR,\ \fB\-s\fR
 331 Enable logging to syslog. On Windows this will attempt to communicate
 332 (over UDP) with a syslog daemon on localhost, which will most likely
 333 not work.
 334
 335 Default: disabled
 336
 337 .SH CONFIGURATION FILE
 338 .P
 339 Any of the command-line options mentioned above can be specified in a
 340 configuration file instead. We first look for \(dqhtsn-importrc\(dq in
 341 the system configuration directory. We then look for a file named
 342 \(dq.htsn-importrc\(dq in the user's home directory. The latter will
 343 override the former.
 344 .P
 345 The user's home directory is simply $HOME on Unix; on Windows it's
 346 wherever %APPDATA% points. The system configuration directory is
 347 determined by Cabal; the \(dqsysconfdir\(dq parameter during the
 348 \(dqconfigure\(dq step is used.
 349 .P
 350 The file's syntax is given by examples in the htsn-importrc.example file
 351 (included with \fBhtsn-import\fR).
 352 .P
 353 Options specified on the command-line override those in either
 354 configuration file.
 355
 356 .SH EXAMPLES
 357 .IP \[bu] 2
 358 Import newsxml.xml into a preexisting sqlite database named \(dqfoo.sqlite3\(dq:
 359
 360 .nf
 361 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 362 .I "              test/xml/newsxml.xml"
 363 Successfully imported test/xml/newsxml.xml.
 364 Imported 1 document(s) total.
 365 .fi
 366 .IP \[bu]
 367 Repeat the previous example, but delete newsxml.xml afterwards:
 368
 369 .nf
 370 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 371 .I "              --remove test/xml/newsxml.xml"
 372 Successfully imported test/xml/newsxml.xml.
 373 Imported 1 document(s) total.
 374 Removed processed file test/xml/newsxml.xml.
 375 .fi
 376 .IP \[bu]
 377 Use a Postgres database instead of the default Sqlite. This assumes
 378 that you have a database named \(dqhtsn\(dq accessible to user
 379 \(dqpostgres\(dq locally:
 380
 381 .nf
 382 .I $ htsn-import --connection-string='dbname=htsn user=postgres' \\\\
 383 .I "              --backend=Postgres test/xml/newsxml.xml"
 384 Successfully imported test/xml/newsxml.xml.
 385 Imported 1 document(s) total.
 386 .fi
 387
 388 .SH BUGS
 389
 390 .P
 391 Send bugs to michael@orlitzky.com.