Re: Dismax - Boosting
Hi Ahmet, In the past we used /spell and if there is not match then we use to get a list of suggestions and then we use to make another call with the first suggestion to get search results. After that we show user both suggestions for the spelling mistake and results of the first suggestion. I think the URL that you provided which has plug in will do help doing that. Is there a way from Solr to directly get the spelling suggestions as well as first suggestion data at the same time? For example: if seach keywork is mooon (typed by mistake instead of moon) the we need all suggestions like: Did you mean: moon, mo, mooing, moonen, soon, mood, moose, moore, spoon, moons? and also the search results for the first suggestion moon. Thanks, Solr User On Fri, Nov 19, 2010 at 6:41 PM, Ahmet Arslan iori...@yahoo.com wrote: The below is my previous configuration which use to work correctly. searchComponent name=spellcheck class=solr.SpellCheckComponent str name=queryAnalyzerFieldTypetextSpell/str lst name=spellchecker str name=namedefault/str str name=fieldsearchFields/str str name=spellcheckIndexDir/solr/qa/tradedata/spellchecker/str str name=buildOnCommittrue/str /lst /searchComponent We use to search only in one field which is searchFields but with implementing dismax we are searching in different fields like title^9.0 subtitle^3.0 author^2.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award. Do we need to modify the above configuration to include all the above fields:??? Please give me an example. Searching and spell checking are independent. For example you can search on 10 fields, and create suggestions from 2 fields. Spell checker accepts one field in its configuration. So you need to populate this field with copyField. Using the fields that you want to use spell checking. And type of this field should be textSpell in your case. You can use above config. In the past we use to query twice to get first the suggestions and then we use to query using the first suggestion to show the data. Is there a way that we can do it in one step? Are you talking about queries that return 0 numFound? Re-executing the search like, described here http://sematext.com/products/dym-researcher/index.html Not out-of-the-box.
Re: Dismax - Boosting
In the past we used /spell and if there is not match then we use to get a list of suggestions and then we use to make another call with the first suggestion to get search results. After that we show user both suggestions for the spelling mistake and results of the first suggestion. I think the URL that you provided which has plug in will do help doing that. Yes, it does exactly about what you describe. Is there a way from Solr to directly get the spelling suggestions as well as first suggestion data at the same time? You can't do that in one step with out-of-the-box solr. You need a plugin for that.
Re: Dismax - Boosting
Hi Ahmet, The below is my previous configuration which use to work correctly. searchComponent name=spellcheck class=solr.SpellCheckComponent str name=queryAnalyzerFieldTypetextSpell/str lst name=spellchecker str name=namedefault/str str name=fieldsearchFields/str str name=spellcheckIndexDir/solr/qa/tradedata/spellchecker/str str name=buildOnCommittrue/str /lst /searchComponent We use to search only in one field which is searchFields but with implementing dismax we are searching in different fields like title^9.0 subtitle^3.0 author^2.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award. Do we need to modify the above configuration to include all the above fields:??? Please give me an example. In the past we use to query twice to get first the suggestions and then we use to query using the first suggestion to show the data. Is there a way that we can do it in one step? Thanks, Murali On Wed, Nov 17, 2010 at 7:00 PM, Ahmet Arslan iori...@yahoo.com wrote: 2. How to use spell checker request handler along with dismax? Just append this at the end of dismax request handler definition: arr name=last-components strspellcheck/str /arr /requestHandler
Re: Dismax - Boosting
The below is my previous configuration which use to work correctly. searchComponent name=spellcheck class=solr.SpellCheckComponent str name=queryAnalyzerFieldTypetextSpell/str lst name=spellchecker str name=namedefault/str str name=fieldsearchFields/str str name=spellcheckIndexDir/solr/qa/tradedata/spellchecker/str str name=buildOnCommittrue/str /lst /searchComponent We use to search only in one field which is searchFields but with implementing dismax we are searching in different fields like title^9.0 subtitle^3.0 author^2.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award. Do we need to modify the above configuration to include all the above fields:??? Please give me an example. Searching and spell checking are independent. For example you can search on 10 fields, and create suggestions from 2 fields. Spell checker accepts one field in its configuration. So you need to populate this field with copyField. Using the fields that you want to use spell checking. And type of this field should be textSpell in your case. You can use above config. In the past we use to query twice to get first the suggestions and then we use to query using the first suggestion to show the data. Is there a way that we can do it in one step? Are you talking about queries that return 0 numFound? Re-executing the search like, described here http://sematext.com/products/dym-researcher/index.html Not out-of-the-box.
Re: Dismax - Boosting
Ahmet, I modified the schema as follows: (Added more fields for faceting) field name=title type=text indexed=true stored=true omitNorms=true / field name=author type=text indexed=true stored=true multiValued=true omitNorms=true / field name=authortype type=text indexed=true stored=true multiValued=true omitNorms=true / field name=isbn13 type=text indexed=true stored=true / field name=isbn10 type=text indexed=true stored=true / field name=material type=text indexed=true stored=true / field name=pubdate type=text indexed=true stored=true / field name=pubyear type=text indexed=true stored=true / field name=reldate type=text indexed=false stored=true / field name=format type=text indexed=true stored=true / field name=pages type=text indexed=false stored=true / field name=desc type=text indexed=true stored=true / field name=series type=text indexed=true stored=true / field name=season type=text indexed=true stored=true / field name=imprint type=text indexed=true stored=true / field name=bisacsub type=text indexed=true stored=true multiValued=true omitNorms=true / field name=bisacstatus type=text indexed=false stored=true / field name=category type=text indexed=true stored=true multiValued=true omitNorms=true / field name=award type=text indexed=true stored=true multiValued=true omitNorms=true / field name=age type=text indexed=true stored=true / field name=reading type=text indexed=true stored=true / field name=grade type=text indexed=true stored=true / field name=path type=text indexed=false stored=true / field name=shortdesc type=text indexed=true stored=true / field name=subtitle type=text indexed=true stored=true omitNorms=true/ field name=price type=float indexed=true stored=true/ field name=author_facet type=string indexed=true stored=true omitNorms=true/ field name=pubyear_facet type=string indexed=true stored=true multiValued=true omitNorms=true/ field name=format_facet type=string indexed=true stored=true omitNorms=true/ field name=series_facet type=string indexed=true stored=true omitNorms=true/ field name=season_facet type=string indexed=true stored=true omitNorms=true/ field name=imprint_facet type=string indexed=true stored=true omitNorms=true/ field name=category_facet type=string indexed=true stored=true multiValued=true omitNorms=true/ field name=award_facet type=string indexed=true stored=true multiValued=true omitNorms=true/ field name=age_facet type=string indexed=true stored=true omitNorms=true/ field name=reading_facet type=string indexed=true stored=true omitNorms=true/ field name=grade_facet type=string indexed=true stored=true omitNorms=true/ field name=price_facet type=string indexed=true stored=true omitNorms=true/ Also added Copy Fields as below: copyField source=author dest=author_facet/ copyField source=pubyear dest=pubyear_facet/ copyField source=format dest=format_facet/ copyField source=series dest=series_facet/ copyField source=season dest=season_facet/ copyField source=imprint dest=imprint_facet/ copyField source=category dest=category_facet/ copyField source=award dest=award_facet/ copyField source=age dest=age_facet/ copyField source=reading dest=reading_facet/ copyField source=grade dest=grade_facet/ copyField source=price dest=price_facet/ With the above changes I am not getting any facet data as a result. Why is that the facet data not returning and what mistake I did with the schema? Thanks, Solr User On Wed, Nov 17, 2010 at 6:42 PM, Ahmet Arslan iori...@yahoo.com wrote: Wow you facet on many fields : author,pubyear,format,series,season,imprint,category,award,age,reading,grade,price The fields you facet on should be untokenized type: string, int, tint date etc. The fields you want full text search, e.g. the ones you specify in qf, pf parameter should be text type. (title subtitle authordesc shortdesc imprint category isbn13 isbn10 format series season bisacsub award) If you have common fields, for example category, you need two copy of that. one string one text. So that you can both full-text search and facet on. Use copy field for this. copyField source=category dest=category_string/ Example document: category: electronic devices query electronic will return it, and facets on category_string will be displayed as : electronic devices (1) not : electronic (1) devices (1) --- On Wed, 11/17/10, Solr User solr...@gmail.com wrote: From: Solr User solr...@gmail.com Subject: Re: Dismax - Boosting To: solr-user@lucene.apache.org Date: Wednesday, November 17, 2010, 11:31 PM Ahmet, Thanks for the reply and it was very helpful. The query that I used before changing to dismax was: /solr/tradecore/spell/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field
Re: Dismax - Boosting
, 11/17/10, Solr User solr...@gmail.com wrote: From: Solr User solr...@gmail.com Subject: Re: Dismax - Boosting To: solr-user@lucene.apache.org Date: Wednesday, November 17, 2010, 11:31 PM Ahmet, Thanks for the reply and it was very helpful. The query that I used before changing to dismax was: /solr/tradecore/spell/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field=gradefacet.field=pricespellcheck=true The above query use to return all the data related to facets, data and also any suggestions related to spelling mistakes properly. The configuration after modifying using dismax is as below: Schema.xml: field name=title type=text indexed=true stored=true omitNorms=true / field name=author type=text indexed=true stored=true multiValued=true omitNorms=true / field name=authortype type=text indexed=true stored=true multiValued=true omitNorms=true / field name=isbn13 type=text indexed=true stored=true / field name=isbn10 type=text indexed=true stored=true / field name=material type=text indexed=true stored=true / field name=pubdate type=text indexed=true stored=true / field name=pubyear type=text indexed=true stored=true / field name=reldate type=text indexed=false stored=true / field name=format type=text indexed=true stored=true / field name=pages type=text indexed=false stored=true / field name=desc type=text indexed=true stored=true / field name=series type=text indexed=true stored=true / field name=season type=text indexed=true stored=true / field name=imprint type=text indexed=true stored=true / field name=bisacsub type=text indexed=true stored=true multiValued=true omitNorms=true / field name=bisacstatus type=text indexed=false stored=true / field name=category type=text indexed=true stored=true multiValued=true omitNorms=true / field name=award type=text indexed=true stored=true multiValued=true omitNorms=true / field name=age type=text indexed=true stored=true / field name=reading type=text indexed=true stored=true / field name=grade type=text indexed=true stored=true / field name=path type=text indexed=false stored=true / field name=shortdesc type=text indexed=true stored=true / field name=subtitle type=text indexed=true stored=true omitNorms=true/ field name=price type=float indexed=true stored=true/ SolrConfig.xml: requestHandler name=dismax class=solr.SearchHandler default=true lst name=defaults str name=defTypedismax/str str name=echoParamsexplicit/str !-- float name=tie0.01/float -- str name=qf title^9.0 subtitle^3.0 author^1.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award /str !-- str name=pf text^0.2 features^1.1 name^1.5 manu^1.4 manu_exact^1.9 /str str name=bf popularity^0.5 recip(price,1,1000,1000)^0.3 /str -- str name=fl * /str !-- str name=mm 2-1 5-2 690% /str int name=ps100/int str name=q.alt*:*/str -- !-- example highlighter config, enable per-query with hl=true -- !-- str name=hl.fltext features name/str -- !-- for this field, we want no fragmenting, just highlighting -- !-- str name=f.name.hl.fragsize0/str -- !-- instructs Solr to return the field itself if no query terms are found -- !-- str name=f.name.hl.alternateFieldname/str str name=f.text.hl.fragmenterregex/str -- !-- defined below -- /lst /requestHandler The query that I used after changing to dismax is: solr/tradecore/select/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field=gradefacet.field=pricespellcheck=true The following are the issues that I am having after modifying to dismax: 1. Facets data is not coming correctly. Lot of extra data is coming. Why and how to fix it? 2. How to use spell checker request handler along with dismax? Thanks, Murali On Mon, Nov 15, 2010 at 5:38 PM, Ahmet Arslan iori...@yahoo.com wrote: 1. Do we need to change the above DisMax handler configuration as per our requirements? Or Leave it as it is? What
Re: Dismax - Boosting
Ahmet, Thanks for the reply and it was very helpful. The query that I used before changing to dismax was: /solr/tradecore/spell/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field=gradefacet.field=pricespellcheck=true The above query use to return all the data related to facets, data and also any suggestions related to spelling mistakes properly. The configuration after modifying using dismax is as below: Schema.xml: field name=title type=text indexed=true stored=true omitNorms=true / field name=author type=text indexed=true stored=true multiValued=true omitNorms=true / field name=authortype type=text indexed=true stored=true multiValued=true omitNorms=true / field name=isbn13 type=text indexed=true stored=true / field name=isbn10 type=text indexed=true stored=true / field name=material type=text indexed=true stored=true / field name=pubdate type=text indexed=true stored=true / field name=pubyear type=text indexed=true stored=true / field name=reldate type=text indexed=false stored=true / field name=format type=text indexed=true stored=true / field name=pages type=text indexed=false stored=true / field name=desc type=text indexed=true stored=true / field name=series type=text indexed=true stored=true / field name=season type=text indexed=true stored=true / field name=imprint type=text indexed=true stored=true / field name=bisacsub type=text indexed=true stored=true multiValued=true omitNorms=true / field name=bisacstatus type=text indexed=false stored=true / field name=category type=text indexed=true stored=true multiValued=true omitNorms=true / field name=award type=text indexed=true stored=true multiValued=true omitNorms=true / field name=age type=text indexed=true stored=true / field name=reading type=text indexed=true stored=true / field name=grade type=text indexed=true stored=true / field name=path type=text indexed=false stored=true / field name=shortdesc type=text indexed=true stored=true / field name=subtitle type=text indexed=true stored=true omitNorms=true/ field name=price type=float indexed=true stored=true/ SolrConfig.xml: requestHandler name=dismax class=solr.SearchHandler default=true lst name=defaults str name=defTypedismax/str str name=echoParamsexplicit/str !-- float name=tie0.01/float -- str name=qf title^9.0 subtitle^3.0 author^1.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award /str !-- str name=pf text^0.2 features^1.1 name^1.5 manu^1.4 manu_exact^1.9 /str str name=bf popularity^0.5 recip(price,1,1000,1000)^0.3 /str -- str name=fl * /str !-- str name=mm 2lt;-1 5lt;-2 6lt;90% /str int name=ps100/int str name=q.alt*:*/str -- !-- example highlighter config, enable per-query with hl=true -- !-- str name=hl.fltext features name/str -- !-- for this field, we want no fragmenting, just highlighting -- !-- str name=f.name.hl.fragsize0/str -- !-- instructs Solr to return the field itself if no query terms are found -- !-- str name=f.name.hl.alternateFieldname/str str name=f.text.hl.fragmenterregex/str -- !-- defined below -- /lst /requestHandler The query that I used after changing to dismax is: solr/tradecore/select/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field=gradefacet.field=pricespellcheck=true The following are the issues that I am having after modifying to dismax: 1. Facets data is not coming correctly. Lot of extra data is coming. Why and how to fix it? 2. How to use spell checker request handler along with dismax? Thanks, Murali On Mon, Nov 15, 2010 at 5:38 PM, Ahmet Arslan iori...@yahoo.com wrote: 1. Do we need to change the above DisMax handler configuration as per our requirements? Or Leave it as it is? What changes? Yes, you need to edit it. At least field names. Does your schema has a field named sku? 2. Do we need make DisMax as a default request handler? Do I need to add attribute default=true to the tag? If you are going to always use it, why not, change it by adding default=true. By doing so you need to add qt parameter in every request. But don't forget to delete other default=true. There can be only one default=true :) 3. I read in the documentation that Default Search Handler and DisMax are the same except that to use DisMaxQueryParser add defType=dismax in the query string. Is there anything else do we need to do? Above dismax
Re: Dismax - Boosting
Wow you facet on many fields : author,pubyear,format,series,season,imprint,category,award,age,reading,grade,price The fields you facet on should be untokenized type: string, int, tint date etc. The fields you want full text search, e.g. the ones you specify in qf, pf parameter should be text type. (title subtitle authordesc shortdesc imprint category isbn13 isbn10 format series season bisacsub award) If you have common fields, for example category, you need two copy of that. one string one text. So that you can both full-text search and facet on. Use copy field for this. copyField source=category dest=category_string/ Example document: category: electronic devices query electronic will return it, and facets on category_string will be displayed as : electronic devices (1) not : electronic (1) devices (1) --- On Wed, 11/17/10, Solr User solr...@gmail.com wrote: From: Solr User solr...@gmail.com Subject: Re: Dismax - Boosting To: solr-user@lucene.apache.org Date: Wednesday, November 17, 2010, 11:31 PM Ahmet, Thanks for the reply and it was very helpful. The query that I used before changing to dismax was: /solr/tradecore/spell/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field=agefacet.field=readingfacet.field=gradefacet.field=pricespellcheck=true The above query use to return all the data related to facets, data and also any suggestions related to spelling mistakes properly. The configuration after modifying using dismax is as below: Schema.xml: field name=title type=text indexed=true stored=true omitNorms=true / field name=author type=text indexed=true stored=true multiValued=true omitNorms=true / field name=authortype type=text indexed=true stored=true multiValued=true omitNorms=true / field name=isbn13 type=text indexed=true stored=true / field name=isbn10 type=text indexed=true stored=true / field name=material type=text indexed=true stored=true / field name=pubdate type=text indexed=true stored=true / field name=pubyear type=text indexed=true stored=true / field name=reldate type=text indexed=false stored=true / field name=format type=text indexed=true stored=true / field name=pages type=text indexed=false stored=true / field name=desc type=text indexed=true stored=true / field name=series type=text indexed=true stored=true / field name=season type=text indexed=true stored=true / field name=imprint type=text indexed=true stored=true / field name=bisacsub type=text indexed=true stored=true multiValued=true omitNorms=true / field name=bisacstatus type=text indexed=false stored=true / field name=category type=text indexed=true stored=true multiValued=true omitNorms=true / field name=award type=text indexed=true stored=true multiValued=true omitNorms=true / field name=age type=text indexed=true stored=true / field name=reading type=text indexed=true stored=true / field name=grade type=text indexed=true stored=true / field name=path type=text indexed=false stored=true / field name=shortdesc type=text indexed=true stored=true / field name=subtitle type=text indexed=true stored=true omitNorms=true/ field name=price type=float indexed=true stored=true/ SolrConfig.xml: requestHandler name=dismax class=solr.SearchHandler default=true lst name=defaults str name=defTypedismax/str str name=echoParamsexplicit/str !-- float name=tie0.01/float -- str name=qf title^9.0 subtitle^3.0 author^1.0 desc shortdesc imprint category isbn13 isbn10 format series season bisacsub award /str !-- str name=pf text^0.2 features^1.1 name^1.5 manu^1.4 manu_exact^1.9 /str str name=bf popularity^0.5 recip(price,1,1000,1000)^0.3 /str -- str name=fl * /str !-- str name=mm 2lt;-1 5lt;-2 6lt;90% /str int name=ps100/int str name=q.alt*:*/str -- !-- example highlighter config, enable per-query with hl=true -- !-- str name=hl.fltext features name/str -- !-- for this field, we want no fragmenting, just highlighting -- !-- str name=f.name.hl.fragsize0/str -- !-- instructs Solr to return the field itself if no query terms are found -- !-- str name=f.name.hl.alternateFieldname/str str name=f.text.hl.fragmenterregex/str -- !-- defined below -- /lst /requestHandler The query that I used after changing to dismax is: solr/tradecore/select/?q=curiouswt=jsonrows=9facet=truefacet.limit=-1facet.mincount=1facet.field=authorfacet.field=pubyearfacet.field=formatfacet.field=seriesfacet.field=seasonfacet.field=imprintfacet.field=categoryfacet.field=awardfacet.field
Re: Dismax - Boosting
2. How to use spell checker request handler along with dismax? Just append this at the end of dismax request handler definition: arr name=last-components strspellcheck/str /arr /requestHandler
Dismax - Boosting
Hi, Currently we are using StandardRequestHandler and the configuration in SolrConfig.xml is as below: requestHandler name=standard class=solr.SearchHandler default=true !-- default values for query parameters -- lst name=defaults str name=echoParamsexplicit/str !-- int name=rows10/int str name=fl*/str str name=version2.1/str -- /lst /requestHandler We would like to switch to DisMax request handler and the configuration in SolrConfig.xml is: requestHandler name=dismax class=solr.SearchHandler lst name=defaults str name=defTypedismax/str str name=echoParamsexplicit/str float name=tie0.01/float str name=qf text^0.5 features^1.0 name^1.2 sku^1.5 id^10.0 manu^1.1 cat^1.4 /str str name=pf text^0.2 features^1.1 name^1.5 manu^1.4 manu_exact^1.9 /str str name=bf popularity^0.5 recip(price,1,1000,1000)^0.3 /str str name=fl id,name,price,score /str str name=mm 2lt;-1 5lt;-2 6lt;90% /str int name=ps100/int str name=q.alt*:*/str !-- example highlighter config, enable per-query with hl=true -- str name=hl.fltext features name/str !-- for this field, we want no fragmenting, just highlighting -- str name=f.name.hl.fragsize0/str !-- instructs Solr to return the field itself if no query terms are found -- str name=f.name.hl.alternateFieldname/str str name=f.text.hl.fragmenterregex/str !-- defined below -- /lst /requestHandler Questions: 1. Do we need to change the above DisMax handler configuration as per our requirements? Or Leave it as it is? What changes? 2. Do we need make DisMax as a default request handler? Do I need to add attribute default=true to the tag? 3. I read in the documentation that Default Search Handler and DisMax are the same except that to use DisMaxQueryParser add defType=dismax in the query string. Is there anything else do we need to do? We are basically moving on to dismax handler and trying to understand what changes we need to make to SolrConfig.xml. I understood what changes need to be made to schema.xml in a different thread on this forum. Thanks, Solr User
Re: Dismax - Boosting
1. Do we need to change the above DisMax handler configuration as per our requirements? Or Leave it as it is? What changes? Yes, you need to edit it. At least field names. Does your schema has a field named sku? 2. Do we need make DisMax as a default request handler? Do I need to add attribute default=true to the tag? If you are going to always use it, why not, change it by adding default=true. By doing so you need to add qt parameter in every request. But don't forget to delete other default=true. There can be only one default=true :) 3. I read in the documentation that Default Search Handler and DisMax are the same except that to use DisMaxQueryParser add defType=dismax in the query string. Is there anything else do we need to do? Above dismax config contains default parameter list. So you don't need to add defType=dismaxqf=title^1.0 text^1.5 ... etc. to the query string. We are basically moving on to dismax handler and trying to understand what changes we need to make to SolrConfig.xml. As you can see in default solrconfig.xml, you can register multiple instances of solr.SearchHandler with different default parameter list and name. default=true one is executed by default. And this can be helpful deciding about dismax params: qf,pf,ps,ps,mm etc http://www.lucidimagination.com/blog/2010/05/23/whats-a-dismax/
