Dead query

Hi: I spent a lot of time creating a query, and it doesn´t return an error, but I run it and doesn´t start. I left it for 23 hours (more than enough, I think) and it didn´t get one single row. I checked with other program (Pentaho spoon, that lets you follow the operation).
The query has a lot of joins, but I wrote some with more, with no problems.
I´d really appreciate any advise on which part is slowing it down
here goes the query:

SELECT
P.apellido
, P.nombre
, CONCAT(P.apellido,", ",P.nombre) AS apellido_nombre
, TDOC.tipo_documento
, P.numero_documento
, P.sexo
, P.cuil
, CONCAT(DOM.calle,IFNULL(DOM.numero,''),IFNULL(DOM.piso,''),IFNULL(DOM.dpto,''),IFNULL(DOM.adicional, ''),IFNULL(DOM.codigo_postal,'')) AS domicilio_personal
, LOCP.localidad AS localidad_particular
, PARTP.partido AS partido_particular
, PROVP.provincia AS provincia_particular
, PAP.pais AS pais_particular
, CASE
WHEN (MONTH(P.fecha_nacimiento) < MONTH(CURRENT_DATE)) THEN YEAR(CURRENT_DATE) - YEAR(P.fecha_nacimiento)
WHEN (MONTH(P.fecha_nacimiento) = MONTH(CURRENT_DATE)) AND (DAY(P.fecha_nacimiento) <= DAY(CURRENT_DATE)) THEN YEAR(CURRENT_DATE) - YEAR(P.fecha_nacimiento)
ELSE (YEAR(CURRENT_DATE) - YEAR(P.fecha_nacimiento)) - 1
END AS edad
,P.fecha_nacimiento

,CO.denominacion
, C.comision
, 'BECAS' as tipo_comision
,PUNT.orden_merito
, CA_D.recomendacion AS ca_d_recomendacion
-- ,TD.tipo_decision AS Directorio
,IF(LIME.tope_edad < YEAR( FROM_DAYS(TO_DAYS(CO.fecha_desde)-TO_DAYS(P.fecha_nacimiento))), 'CON EXCEPCION' , NULL) AS excepcion_por_edad

,P.telefono_personal AS telefono_part
,CONCAT(IFNULL(LT.telefono_pais,''),"-",IFNULL(LT.telefono_area,''),"-", IFNULL(LT.telefono_caracteristica,''),"-",LT.telefono_numero," int ",IFNULL(LT.telefono_interno,'')) AS telefono_Lab
,P.email_personal AS email_personal
,LT.email AS 'email-lab'
/* ,PCE.dato AS PCEDATO
,PCT.dato AS PCTTDATO*/

, GA.gran_area AS GRAN_AREA
, DIS.disciplina AS DIS_PRI
, DIS2.disciplina AS DIS_SEC
, DISDES.disciplina_desagregada AS DIS_DESAGREGADA
, DISDES.codigo AS DIS_DESAGREGADA_COD
, DISDES2.disciplina_desagregada AS DIS_DESAGREGADA_SEC
, DISDES2.codigo AS DIS_DESAGREGADA_SEC_COD

, org.unidad AS Lugar_trabajo
, UO1.unidad AS nivel_1
, UO2.unidad AS nivel_2
, UO3.unidad AS nivel_3
, UO4.unidad AS nivel_4
, LOC.localidad AS LOCALIDAD_LT
, PART.partido AS PARTIDO_LT
, PROV.provincia AS PROVINCIA_LT
, PROV.codigo AS COD_PROVINCIA_LT
, PA. pais AS PAIS_LT
, PA. codigo_pais AS COD_PAIS_LT

, E.estado AS estado_tramite


FROM PERSONA P
INNER JOIN TIPO_DOCUMENTO TDOC ON (P.tipo_documento_tk=TDOC.tk)
LEFT JOIN DOMICILIO DOM ON (DOM.persona_tk=P.tk)
LEFT JOIN PAIS PAP ON (PAP.tk=DOM.pais_tk)
LEFT JOIN LOCALIDAD LOCP ON (LOCP.tk=DOM.localidad_tk)
LEFT JOIN PARTIDO PARTP ON (LOCP.partido_tk=PARTP.tk)
LEFT JOIN PROVINCIA PROVP ON (PARTP.provincia_tk=PROVP.tk)

INNER JOIN TRAMITE T ON (P.propietario_tk=T.propietario_tk)
LEFT JOIN ESTADO E ON (E.tk = T.estado_tk)
INNER JOIN LUGAR_TRABAJO_TRAMITE LTT ON (T.tk = LTT.tramite_tk)
INNER JOIN LUGAR_TRABAJO LT ON (LTT.lugar_trabajo_tk = LT.tk)
INNER JOIN CONVOCATORIA CO ON (CO.tk = T.convocatoria_tk)
INNER JOIN COMISION_TRAMITE CT ON (T.tk = CT.tramite_tk)
INNER JOIN COMISION C ON (CT.comision_tk = C.tk AND C.tipo_comision_tk=4)
LEFT JOIN OBJETO_EVALUACION OBJE ON CO.objeto_evaluacion_tk=OBJE.tk
LEFT JOIN LIMITE_EDAD LIME ON LIME.objeto_evaluacion_tk=OBJE.tk

LEFT JOIN ORDEN_MERITO_TRAMITE PUNT ON (PUNT.tramite_tk = T.tk)

LEFT JOIN
(SELECT
CT.tramite_tk
, CD.tk AS comision_dictamen_tk
, CD.tipo_dictamen_tk
,CASE
WHEN CD.tipo_recomendacion_tk = 14
THEN 'RECO.'
WHEN CD.tipo_recomendacion_tk = 13
THEN 'NO RECO.'
ELSE ''
END AS recomendacion ,
CD.tipo_recomendacion_tk
FROM TRAMITE T
INNER JOIN COMISION_TRAMITE CT ON (T.tk = CT.tramite_tk)
INNER JOIN COMISION C ON (CT.comision_tk = C.tk)
LEFT JOIN COMISION_DICTAMEN CD ON (CT.tk = CD.comision_tramite_tk)
WHERE (T.tk = CT.tramite_tk)
AND (CD.tipo_dictamen_tk = 1)
AND (C.tipo_comision_tk <> 2)
AND ( CD.estado_comision_dictamen_tk IN (4,6))) CA_D ON (CA_D.tramite_tk = CT.tramite_tk)

INNER JOIN DATO_ACADEMICO_TRAMITE DAT ON (T.tk = DAT.tramite_tk)
LEFT JOIN DISCIPLINA DIS ON (DIS.tk = DAT.disciplina_tk)
LEFT JOIN DISCIPLINA_DESAGREGADA DISDES ON (DISDES.tk = DAT.disciplina_desagregada_tk)
LEFT JOIN DISCIPLINA DIS2 ON (DIS2.tk = DAT.disciplina_sec_tk)
LEFT JOIN DISCIPLINA_DESAGREGADA DISDES2 ON (DISDES2.tk = DAT.disciplina_desagregada_sec_tk)
LEFT JOIN GRAN_AREA AS GA ON (DIS.gran_area_tk=GA.tk)

LEFT JOIN DIRECTOR_TRAMITE_PRESENTADO DT ON (DT.tramite_tk = T.tk )
LEFT JOIN DIRECTOR_PRESENTADO DIR ON (DIR.tk = DT.director_tk AND DIR.tipo_director_tk = 1)
LEFT JOIN UNIDAD_ORGANIZATIVA org ON (org.tk = LT.unidad_organizativa_tk)
LEFT JOIN UNIDAD_ORGANIZATIVA UO1 ON (UO1.tk = SUBSTR(org.unidad, 1, 7))
LEFT JOIN UNIDAD_ORGANIZATIVA UO2 ON (UO2.tk = SUBSTR(org.unidad, 9, 7))
LEFT JOIN UNIDAD_ORGANIZATIVA UO3 ON (UO3.tk = SUBSTR(org.unidad, 17, 7))
LEFT JOIN UNIDAD_ORGANIZATIVA UO4 ON (UO4.tk = SUBSTR(org.unidad, 25, 7))
LEFT JOIN LOCALIDAD LOC ON (org.localidad_tk=LOC.tk)
LEFT JOIN PARTIDO PART ON (LOC.partido_tk=PART.tk)
LEFT JOIN PROVINCIA PROV ON (PART.provincia_tk=PROV.tk)
LEFT JOIN PAIS PA ON (PROV.pais_tk=PA.tk)

WHERE C.tipo_comision_tk <> 2
AND LIME.objeto_evaluacion_tk IS NOT NULL
AND CO.tk IN (104201102,103201102,105201102,104201101,103201101,105201101)
ORDER BY C.comision,CO.tk,PUNT.orden_merito;

Thank you

Place an EXPLAIN in front of your query and execute it and post the result here within a CODE /CODE block (the # button above).

We need to see what your MySQL instance is doing when it is executing your query.

But some suggestions are:
1. one of the tables in the query is missing an index on the join column so it has to perform a table scan to check if there are any matching records, if there are a lot of rows then this will become very costly.

2. join conditions with calculations in them like:
UO1.tk = SUBSTR(org.unidad, 1, 7)
are also a performance killer since they can't use an index on org.unidad properly.

3. In one of the joins the two columns joined are not of the exact same type also causing a table scan.

But without the execution plan from the EXPLAIN above we don't know where to look.

Thanks for the help. Items 1 and 2 where what was wrong.
2 tables had no indexes, and I split the query in 4. now they finish in 60 seconds (very large tables)
cheers

El Multiversista